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Project Title:  Zero-G Studies of Few-Body and Many-Body Physics Reduce
Images: icon  Fiscal Year: FY 2020 
Division: Physical Sciences 
Research Discipline/Element:
Physical Sciences: FUNDAMENTAL PHYSICS--Fundamental physics 
Start Date: 04/01/2014  
End Date: 08/31/2021  
Task Last Updated: 05/18/2020 
Download report in PDF pdf
Principal Investigator/Affiliation:   Cornell, Eric  Ph.D. / University of Colorado 
Address:  JILA 
440 UCB 
Boulder , CO 80309-0440 
Email: Cornell@jila.colorado.edu 
Phone: 303-492-6281  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of Colorado 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Engels, Peter  Ph.D. Washington State University, Pullman 
Ho, Tin-Lun  Ph.D. Ohio State University 
Project Information: Grant/Contract No. JPL 1502690 
Responsible Center: NASA JPL 
Grant Monitor: Israelsson, Ulf  
Center Contact:  
ulf.e.israelsson@jpl.nasa.gov 
Solicitation: 2013 Fundamental Physics NNH13ZTT002N (Cold Atom Laboratory--CAL) 
Grant/Contract No.: JPL 1502690 
Project Type: FLIGHT 
Flight Program: ISS 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Program--Element: FUNDAMENTAL PHYSICS--Fundamental physics 
Flight Assignment/Project Notes: NOTE: End date changed to 8/31/2021 per U. Israelsson/JPL (Ed., 5/12/2020)

NOTE: End date changed to 4/30/2020 per PI (Ed., 5/1/19)

Task Description: Future advances in both technology and fundamental science will hinge on a better understanding of the weird effects of quantum mechanics on collections of electrons, atoms, molecules, and so on. In some cases, experiments probing this so-called “quantum few-body and many-body physics” can be more readily accomplished in the weightless environment found in an orbiting laboratory. We propose a staged series of experiments, including (1) “first science” experiment, to be performed in the Cold Atom Laboratory (CAL) flying in the International Space Station (ISS) first-generation, to answer a question in few-body quantum physics that can’t be performed in a ground-based laboratory: how universal are the weakly bound clusters of three atoms known as Efimov trimers? In a weightless environment, experiments can be performed at very low densities and temperatures, the perfect conditions for these exotic but fragile quantum states to form. (2) Bose gases with “infinite” interactions. As interactions between atoms become stronger, there is a crossover between gas-phase and liquid behavior. In ultra-cold atoms, the crossover is between a quantum liquid and a quantum gas. (3) Highly rotating quantum gases. Many of the most exotic and unexplored predicted states of matter occur in the presence of very strong magnetic fields, for electrons, or high rates of rotation, for neutral particles. We will explore Quantum Hall physics in highly rotating Bose and Fermi gases. Experiments (2) and (3) will benefit significantly from the longer expansion times and weaker traps possible in weightlessness. Preliminary versions of both experiments will be done in a ground-based laboratory in order to establish the foundation for future flight-based experiments.

Research Impact/Earth Benefits: Physics is the discipline that provides understanding of biology and chemistry at the most microscopic level, and the area within physics most relevant to chemistry and biology is “few-body physics.” It is an often neglected portion of physics, because it is so difficult to do! An important way to make progress is to simplify, simplify, simplify: to come up with model systems in which we can make progress that can later be applied to human-centric disciplines like biology, and develop exotic and useful new materials. A promising way to simplify is to study matter at lower temperature, and lower densities. The Cold-Atom Lab (CAL) flying in the International Space Station (ISS) is where we will reach the lowest possible temperatures, and low densities, to do our studies of simple, yet intricate (think “snowflakes”) clusters of three or four atoms. We have been doing prefatory experiments and calculations here on Earth. Not at as low temperature, but still cold enough to help us learn things we will need to know to do the space experiments. While CAL is now in flight, we have been participating in the effort to remotely tune it up for maximum performance.

Task Progress & Bibliography Information FY2020 
Task Progress: Our collaboration has actively contributed to CAL through three different lines of work: through calibration measurements performed with CAL and accompanying numerical modeling, through ongoing discussions with the Jet Propulsion Laboratory (JPL) team about the operational performance of the CAL instrument onboard the ISS, and through performing ground based measurements at both JILA and Washington State University (WSU) that optimize experimental procedures for the planned few-body measurements.

In 2019 CAL’s operations on board the ISS continued with Science Module 2 (SM2) until December 2019, when Science Module 3 (SM3) was launched to the ISS as an AI-enabled replacement of SM2. With SM2, we successfully used Rb-87 to test the traps needed to perform our planned few-body studies with potassium, confirming that our model replicated the trapping frequencies found for a trap with the necessary magnetic field characteristics. At the end of 2019, SM3 was launched to the ISS and installed at the start of 2020. The new science module has required a new numerical model and new calibrations. We have updated our calculations accordingly, both with basic Mathematica and with a new software package. We are currently developing strategies with the JPL team to calibrate the bias fields of SM3 to ensure accurate models. Along those lines, we have discovered a clear discrepancy with the manufacturer’s specification of one of the magnetic coil pairs (the Fast Feshbach coils), which we believe is due to an error in the manufacturer’s calibration routine. We plan to resolve this soon together with the JPL team. A deep understanding of CAL’s performance and magnetic field stability is key for the optimization of the planned few-body experiments.

During the operation of SM2 it became clear that a microwave generator used to effect state changes in Rb is malfunctioning. Pinpointing the exact cause of the malfunctioning was challenging due to the limited telemetry available. To help analyze this problem, members of our team, including Eric Cornell, Peter Engels, and Maren Mossman, traveled to JPL in October 2019 to serve as independent advisors. In discussions with JPL scientists and engineers, we were able to suggest a series of tests that in the end were able to pinpoint the most likely problem. Ground based tests performed by JPL have been able to duplicate this error and plans for correcting this problem are currently being discussed at JPL. Correcting this problem is an important step not only for facilitating experiments for potassium, but also for specific Rb experiments that require the flexibility of changing hyperfine states between different manifolds.

Furthermore, our collaboration has continued to perform extensive accompanying studies on the ground in the Cornell lab at JILA and the Engels lab at WSU. While JILA has focused on experiments with 39K, the Engels lab at WSU has continued to work towards the formation of a quantum degenerate 41K gas. The variety of experimental approaches used in the ground-based studies at JILA and WSU allows us to validate a broad variety of aspect relevant for CAL. These studies not only serve to optimize the experimental procedures of our few-body experiments with CAL but have also produced a surprising science result. At JILA, our team has performed precision measurements with 39K that have resulted in an unprecedented calibration of the Feshbach resonance and knowledge of the exact scattering length at which the first Efimov trimer crosses the free-atom threshold. The experiments have been accompanied by theoretical investigations performed by Jose D’Incao. Compared to the previously known results, the new results are more precise by two orders of magnitude. This has enabled us to perform a precision measurement of the first Efimov resonance, leading to the surprising finding that a previously assumed “van-der-Waals universality” in the system is unambiguously broken. A theoretical analysis by Jose D’Incao has confirmed this surprising result. Furthermore, we have explored the temperature and density limits that constrain the observation of the first Efimov state in ground-based experiments. This work was published in Physical Review Letters in 2019 https://doi.org/10.1103/PhysRevLett.123.233402 . These studies have direct consequences for the planned measurement of the second, next higher Efimov state with CAL -- that can only been done with the flight module onboard the ISS -- by informing us about the required parameter regimes and optimal procedures.

Results of our research activities were presented at several conferences. In April 2019, we presented a poster at the NASA Fundamental Physics Workshop held in Washington DC. In December 2019, members of our team, Peter Engels and Maren Mossman, attended the BECCAL meeting in Ulm, Germany where we presented our planned Efimov studies with CAL and proposed future studies creating quantum droplets in microgravity. In addition to this, Peter Engels presented two talks on our work with CAL: one during the Physics Slam event at WSU’s Conference for Undergraduate Women in Physics (CUWiP) and the other at the WSU-hosted Northwest Quantum Nexus workshop for Quantum Computing, Sensing and Simulation with Cold Atoms.

Professor Jason Ho and his team at Ohio State University have been looking forward, both towards future more elaborate Cold-Atom work, and towards applications of related concepts to important topics like materials design and quantum information. Recent work focused in particular on how quantum simulation can be used to solve computationally difficult problems such as how to find find the ground state and the excitations of a doped antiferromagnet. Other results explained the properties of one of the most exotic new material currently under exploration, twisted bilayer graphene. This system has recently been shown to be a superconductor and could have interesting technological applications.

In summary, our continued experiments at JILA and at WSU are providing important benchmarks for the CAL apparatus, while our work with the CAL flight module onboard the ISS is contributing to a full characterization of the instrument in preparation for the planned Efimov measurements. As SM3 continues to be calibrated, we will optimize our model and procedures accordingly. Regarding the technical aspects of the CAL instrument, we will continue to work with JPL researchers on the microwave slice development before a potential launch of a new microwave module later this year.

Bibliography Type: Description: (Last Updated: 05/19/2020)  Show Cumulative Bibliography Listing
 
Articles in Peer-reviewed Journals Chapurin R, Xie X, Van de Graaff MJ, Popowski JS, D'Incao JP, Julienne PS, Ye J, Cornell EA. "Precision test of the limits to universality in few-body physics." Phys Rev.Lett. 2019 Dec 6;123:233402. https://doi.org/10.1103/PhysRevLett.123.233402 , Dec-2019
Dissertations and Theses Xie X. "Precise Calibrations of Few-Body Physics in Potassium-39: Experiment and Theory." University of Colorado, Boulder, April 2020. , Apr-2020
Project Title:  Zero-G Studies of Few-Body and Many-Body Physics Reduce
Images: icon  Fiscal Year: FY 2019 
Division: Physical Sciences 
Research Discipline/Element:
Physical Sciences: FUNDAMENTAL PHYSICS--Fundamental physics 
Start Date: 04/01/2014  
End Date: 04/30/2020  
Task Last Updated: 04/27/2019 
Download report in PDF pdf
Principal Investigator/Affiliation:   Cornell, Eric  Ph.D. / University of Colorado 
Address:  JILA 
440 UCB 
Boulder , CO 80309-0440 
Email: Cornell@jila.colorado.edu 
Phone: 303-492-6281  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of Colorado 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Engels, Peter  Ph.D. Washington State University, Pullman 
Ho, Tin-Lun  Ph.D. Ohio State University 
Project Information: Grant/Contract No. JPL 1502690 
Responsible Center: NASA JPL 
Grant Monitor: Israelsson, Ulf  
Center Contact:  
ulf.e.israelsson@jpl.nasa.gov 
Solicitation: 2013 Fundamental Physics NNH13ZTT002N (Cold Atom Laboratory--CAL) 
Grant/Contract No.: JPL 1502690 
Project Type: FLIGHT 
Flight Program: ISS 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Program--Element: FUNDAMENTAL PHYSICS--Fundamental physics 
Flight Assignment/Project Notes: NOTE: End date changed to 4/30/2020 per PI (Ed., 5/1/19)

Task Description: Future advances in both technology and fundamental science will hinge on a better understanding of the weird effects of quantum mechanics on collections of electrons, atoms, molecules, and so on. In some cases, experiments probing this so-called “quantum few-body and many-body physics” can be more readily accomplished in the weightless environment found in an orbiting laboratory. We propose a staged series of experiments, including (1) “first science” experiment, to be performed in the Cold Atom Laboratory (CAL) flying in the International Space Station (ISS) first-generation, to answer a question in few-body quantum physics that can’t be performed in a ground-based laboratory: how universal are the weakly bound clusters of three atoms known as Efimov trimers? In a weightless environment, experiments can be performed at very low densities and temperatures, the perfect conditions for these exotic but fragile quantum states to form. (2) Bose gases with “infinite” interactions. As interactions between atoms become stronger, there is a crossover between gas-phase and liquid behavior. In ultra-cold atoms, the crossover is between a quantum liquid and a quantum gas. (3) Highly rotating quantum gases. Many of the most exotic and unexplored predicted states of matter occur in the presence of very strong magnetic fields, for electrons, or high rates of rotation, for neutral particles. We will explore Quantum Hall physics in highly rotating Bose and Fermi gases. Experiments (2) and (3) will benefit significantly from the longer expansion times and weaker traps possible in weightlessness. Preliminary versions of both experiments will be done in a ground-based laboratory in order to establish the foundation for future flight-based experiments.

Research Impact/Earth Benefits: Physics is the discipline that provides understanding of biology and chemistry at the most microscopic level, and the area within physics most relevant to chemistry and biology is “few-body physics.” It is an often neglected portion of physics, because it is so difficult to do! An important way to make progress is to simplify, simplify, simplify: to come up with model systems in which we can make progress that can later be applied to human-centric disciplines like biology, and develop exotic and useful new materials. A promising way to simplify is to study matter at lower temperature, and lower densities. The Cold-Atom Lab (CAL) flying in the International Space Station (ISS) is where we will reach the lowest possible temperatures, and low densities, to do our studies of simple, yet intricate (think “snowflakes”) clusters of three or four atoms. While CAL is being prepared for flight, we have been doing prefatory experiments and calculations here on Earth. Not at as low temperature, but still cold enough to help us learn things we will need to know to do the space experiments.

Task Progress & Bibliography Information FY2019 
Task Progress: The goal of this project is the investigation of exotic few-body physics and novel quantum states, exploiting the specific strengths of NASA’s Cold Atom Laboratory (CAL) onboard the International Space Station (ISS). CAL is a unique experimental platform that utilizes the near weightlessness onboard the ISS and makes it possible to create atomic clouds that are both very dilute and extremely cold. These clouds are governed by intricate quantum mechanical effects. While Earth-based experiments with quantum gases have led to many revolutionary experiments over the past few years, the microgravity environment in which CAL is placed will allow us to push the boundaries significantly further.

In 2018 CAL’s operation on board the ISS has begun. We have been in constant discussions with the Jet Propulsion Laboratory (JPL) team to assist with and keep track of the calibration procedures that are being performed to evaluate the CAL instrument onboard the ISS. While science data runs with potassium are currently awaiting the optimization of potassium evaporation routines by the JPL team, the current calibrations performed using Rb in the CAL flight module already inform us about essential performance figures of CAL such as the vacuum limited lifetime, atom number stability, imaging capabilities, etc. A deep understanding of CAL’s performance is key for the optimization of the planned Efimov experiments.

Furthermore, our collaboration has performed extensive studies on the ground in the labs at JILA and Washington State University (WSU). These studies not only serve to optimize the experimental procedures of our Efimov experiments with CAL but have also produced a surprising science result. At JILA, we have performed precision measurements with 39K that have resulted in an unprecedented calibration of the Feshbach resonance and knowledge of the exact scattering length at which the first Efimov trimer crosses the free-atom threshold. The experiments have been accompanied by theoretical investigations performed by Jose D’Incao. Compared to the previously known results, the new results are more precise by two orders of magnitude. This has enabled us to perform a precision measurement of the first Efimov resonance, leading to the surprising finding that a previously assumed “van-der-Waals universality” in the system is unambiguously broken. A theoretical analysis by our collaborator Jose D’Incao has confirmed this surprising result. Furthermore, we have explored the temperature and density limits that constrain the observation of the first Efimov state in ground-based experiments. These studies have direct consequences for the planned measurement of the second, next higher Efimov state with CAL -- that can only been done with the flight module onboard the ISS -- by informing us about the required parameter regimes and optimal procedures.

While JILA has focused on experiments with 39K, efforts at WSU have been directed towards the formation of a quantum degenerate 41K cloud. This is the potassium isotope that will be used in later stages of CAL for extended Efimov studies and for atom interferometry experiments. The variety of experimental approaches used in the ground based studies at JILA and WSU allows us to validate a broad variety of aspect relevant for CAL. For example, laser cooling of the bosonic potassium isotopes poses particular difficulties related to the level structure of these atoms. We are developing optimized cooling strategies to address these difficulties and to provide an optimized starting point for the generation of quantum degenerate potassium clouds with CAL.

In summary, our ground based experiments at JILA and at WSU provide important benchmark results for the CAL apparatus. As more and more calibration and machine characterization is performed with the CAL flight module, we continue to update our proposed experimental procedures for the planned Efimov measurements. Our experiments have also delivered important science results, such as the characterization of a Feshbach resonance with a record precision (improving previous results by a factor of 100) as well as the unambiguous confirmation of breaking of a “van-der-Waals universality” that in the past had been an important paradigm.

In anticipation of the next-generation of CAL, we’ve been doing extensive theoretical work at Ohio State University, with a goal of understanding the exotic states of matter than can result when ultra-cold atoms rotate very rapidly. Generically known as “quantum Hall states,” the various excitations of these states are generally regarded as examples for hardware components for fault tolerant quantum computers.

Effort has been focused on (i) realizing quantum Hall states cold atoms in different platforms, (ii) the manipulation of the quasi-particles of the quantum Hall states, and (iii) quantum dynamics of multi-component quantum Hall states.

For Project (i),we study the feasibility of realizing quantum Hall states in rotating potentials generated by Digital Mirror Devices, while K.H. Chen studies the creation of quantum Hall states using photons, motivated by the recent experiments of Jon Simon’s group at University of Chicago to create quantum Hall states with photons in cavities. The latter work has led to the discovery of a “super-degenerate” quantum Hall regime in photonic systems, where all the higher Landau levels (such as those in Simon’s experiment) are made degenerate with the lowest one by simply adjusting the configurations of the laser beam. The degeneracy of “super-degenerate” manifold is considerably larger than those of the usual quantum Hall states, and is an exciting regime to study quantum many-body physics.

For Project (ii), we worked on the protocols to engineer singlet and triplet spin states of quasi-particles in a fully filled Landau levels with both spin up and spin down fermions. The creation and manipulation of these spin states with precision is crucial for the study of non-abelian exchanges processes in these systems, a process of key importance in quantum information processing.

For Project (iii), we have been studying the quantum evolution of ferromagnetic quantum Hall states in a quadrupolar field. The ferromagnetic quantum Hall state will emerge in a two-component fermions each in a half-filled lowest Landau level. The particular kind of quantum evolution we study will generate Skyrmion excitations in this ferromagnet. This work is in progress.

Bibliography Type: Description: (Last Updated: 05/19/2020)  Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Xie X, Chapurin R, van de Graaff M, Lopez-Abadia C, Popowski J, Ye J, Cornell E. "Precise Characterization of Few-body Interactions in 39K." Presented at 49th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics (DAMOP) APS Meeting, Ft Lauderdale, FL, May 28-June 1, 2018. Session E01: Poster Session I.

Bulletin of the American Physical Society. 2018 Jun;63(5): Abstract E01.00113. http://meetings.aps.org/Meeting/DAMOP18/Session/E01.113 , Jun-2018

Abstracts for Journals and Proceedings Chapurin R, Xie X, van de Graaff M, Lopez-Abadia C, Popowski J, Ye J, Cornell E. "Precision Spectroscopy of Feshbach and Efimov Resonances of 39K." Presented at 49th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics (DAMOP) APS Meeting, Ft Lauderdale, FL, May 28-June 1, 2018. Session E01: Poster Session I. Session U08: Precision Measurements.

Bulletin of the American Physical Society. 2018 Jun;63(5):Abstract U08.00004. http://meetings.aps.org/Meeting/DAMOP18/Session/U08.4 , Jun-2018

Abstracts for Journals and Proceedings Cornell E. "Ground- and Space-Based Experiments in Few-Body Quantum Mechanics: An update on work towards precision measurement of Efimov physics in microgravity." NASA Fundamental Physics Workshop, La Jolla, CA, April 9-11, 2018.

NASA Fundamental Physics Workshop, La Jolla, CA, April 9-11, 2018. , Apr-2018

Articles in Peer-reviewed Journals Colussi VE, Corson JP, D'Incao JP. "Dynamics of three-body correlations in quenched unitary Bose gases." Phys Rev Lett. 2018 Mar 9;120(10):100401. https://doi.org/10.1103/PhysRevLett.120.100401 ; PubMed PMID: 29570331 , Mar-2018
Articles in Peer-reviewed Journals D'Incao JP, Wang J, Colussi VE. "Efimov physics in qenched unitary Bose gases." Phys Rev Lett. 2018 Jul 13;121(2):023401. https://doi.org/10.1103/PhysRevLett.121.023401 ; PubMed PMID: 30085687 , Jul-2018
Articles in Peer-reviewed Journals Colussi VE, van Zwol BE, D'Incao JP, Kokkelmans SJJMF. "Bunching, clustering, and the buildup of few-body correlations in a quenched unitary Bose gas." Physical Review A. 2019 Apr;99(4):043604. https://doi.org/10.1103/PhysRevA.99.043604 , Apr-2019
Articles in Peer-reviewed Journals Yin XY, Ho T-L, Cui X. "Majorana edge state in number-conserving Fermi gas with tunable p-wave interaction." New Journal of Physics. 2019 Jan;21:013004. https://doi.org/10.1088/1367-2630/aaec35 , Jan-2019
Articles in Peer-reviewed Journals Zhang J, Ho T-L. "Potential scattering on a spherical surface." Journal of Physics B: Atomic, Molecular and Optical Physics. 2018 Jun;51(11):115301. https://doi.org/10.1088/1361-6455/aabc34 , Jun-2018
Dissertations and Theses Chapurin R. "Precise Measurements of Few-Body Physics in Ultracold 39K Bose Gas." Dissertation, JILA, University of Colorado, Boulder, April 2019. , Apr-2019
Dissertations and Theses Mossman M. "Nonlinear dynamics and shock structures in elongated Bose-Einstein condensates." Dissertation, Washington State University, April 15, 2019. , Apr-2019
Project Title:  Zero-G Studies of Few-Body and Many-Body Physics Reduce
Images: icon  Fiscal Year: FY 2018 
Division: Physical Sciences 
Research Discipline/Element:
Physical Sciences: FUNDAMENTAL PHYSICS--Fundamental physics 
Start Date: 04/01/2014  
End Date: 04/30/2019  
Task Last Updated: 04/27/2018 
Download report in PDF pdf
Principal Investigator/Affiliation:   Cornell, Eric  Ph.D. / University of Colorado 
Address:  JILA 
440 UCB 
Boulder , CO 80309-0440 
Email: Cornell@jila.colorado.edu 
Phone: 303-492-6281  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of Colorado 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Engels, Peter  Ph.D. Washington State University, Pullman 
Ho, Tin-Lun  Ph.D. Ohio State University 
Project Information: Grant/Contract No. JPL 1502690 
Responsible Center: NASA JPL 
Grant Monitor: Israelsson, Ulf  
Center Contact:  
ulf.e.israelsson@jpl.nasa.gov 
Solicitation: 2013 Fundamental Physics NNH13ZTT002N (Cold Atom Laboratory--CAL) 
Grant/Contract No.: JPL 1502690 
Project Type: FLIGHT 
Flight Program: ISS 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Program--Element: FUNDAMENTAL PHYSICS--Fundamental physics 
Task Description: Future advances in both technology and fundamental science will hinge on a better understanding of the weird effects of quantum mechanics on collections of electrons, atoms, molecules, and so on. In some cases, experiments probing this so-called “quantum few-body and many-body physics” can be more readily accomplished in the weightless environment found in an orbiting laboratory. We propose a staged series of experiments, including (1) “first science” experiment, to be performed in the Cold Atom Laboratory (CAL) flying in the International Space Station (ISS) first-generation, to answer a question in few-body quantum physics that can’t be performed in a ground-based laboratory: how universal are the weakly bound clusters of three atoms known as Efimov trimers? In a weightless environment, experiments can be performed at very low densities and temperatures, the perfect conditions for these exotic but fragile quantum states to form. (2) Bose gases with “infinite” interactions. As interactions between atoms become stronger, there is a crossover between gas-phase and liquid behavior. In ultra-cold atoms, the crossover is between a quantum liquid and a quantum gas. (3) Highly rotating quantum gases. Many of the most exotic and unexplored predicted states of matter occur in the presence of very strong magnetic fields, for electrons, or high rates of rotation, for neutral particles. We will explore Quantum Hall physics in highly rotating Bose and Fermi gases. Experiments (2) and (3) will benefit significantly from the longer expansion times and weaker traps possible in weightlessness. Preliminary versions of both experiments will be done in a ground-based laboratory in order to establish the foundation for future flight-based experiments.

Research Impact/Earth Benefits: Physics is the discipline that provides understanding of biology and chemistry at the most microscopic level, and the area within physics most relevant to chemistry and biology is “few-body physics.” It is an often neglected portion of physics, because it is so difficult to do! An important way to make progress is to simplify, simplify, simplify: to come up with model systems in which we can make progress that can later be applied to human-centric disciplines like biology, and develop exotic and useful new materials. A promising way to simplify is to study matter at lower temperature, and lower densities. The Cold-Atom Lab (CAL) flying in the International Space Station (ISS) is where we will reach the lowest possible temperatures, and low densities, to do our studies of simple, yet intricate (think “snowflakes”) clusters of three or four atoms. While CAL is being prepared for flight, we have been doing prefatory experiments and calculations here on Earth. Not at as low temperature, but still cold enough to help us learn things we will need to know to do the space experiments.

Task Progress & Bibliography Information FY2018 
Task Progress: The goal of this project is the investigation of exotic few-body physics and novel quantum states, exploiting the specific strengths of NASA’s Cold Atom Laboratory (CAL) onboard the International Space Station (ISS). CAL is a unique experimental platform that utilizes the near weightlessness onboard the ISS and makes it possible to create atomic clouds that are both very dilute and extremely cold. These clouds are governed by intricate quantum mechanical effects. While Earth-based experiments with quantum gases have led to many revolutionary experiments over the past few years, the microgravity environment in which CAL is placed will allow us to push the boundaries significantly further.

Our initial work has focused on the study of exotic three-body states. In 1970, theoretical physicist Vitaly Efimov predicted that, under certain conditions, three atoms can form a bound state even if the attractions between just two atoms are too weak to cause binding. CAL will provide a unique new environment for testing few-body systems in previously inaccessible regimes that are prerequisite for the next generation of Efimov experiments. We have worked diligently to prepare an experimental plan for research both at the ground test bed and with the CAL apparatus on board the ISS.

Over the past year, we have also extended the scope of our work to investigate quantum droplets using the CAL apparatus. Quantum droplets are an intriguing state of quantum matter that can be created out of a dilute-gas BEC. Quantum droplets are fluids, rather than gases, which means that they are characterized by a constant density and exhibit pronounced surface effects. They have a sparse excitation spectrum, making them essentially zero-temperature objects. Furthermore, they are self-bound, implying that they are stable, non-dispersing objects even in the absence of a trap. Their self-bound nature makes them ideal candidates for studies in microgravity: only in microgravity is it possible to investigate these droplets in the absence of any confinement, and thus in their purest form. Our goal is to measure basic properties of these systems, including their excitation spectrum, surface effects, and lifetime in microgravity, using the existing technology of CAL.

In the meantime, we have been working on some ground-based measurements that are complementary to our planned CAL-based measurements. We have made very precise studies of how ultracold gases (in particular, Potassium-39) collide as one changes the ambient magnetic field. In particular, we have determined the value of magnetic field at which an Efimov resonance occurs. We are in the midst of extensive calculations that predict the difference in magnetic field between this Efimov and the next highest up. That next resonance can not be accurately studied in a ground-based experiment, because temperatures on Earth, although very cold, are not cold enough. In the much colder temperature accessible on CAL, below one nanokelvin, we anticipate making the second, critical half of the comparison. These combined measurements will yield the most precise ever study of resonant three-body quantum mechanics.

In addition to our experimental work on Efimov physics, we have been doing some more purely theoretical investigations into rapidly rotating ultracold gases. Our hope is that these studies will provide the ground work for a more advanced set of ISS-based cold-atom experiments early in the next decade. These future experiments, combined with the Efimov studies planned for next year, will yield insight and understanding into the nature of the quantum mechanics of interacting particles. Quantum mechanics is the science of the very, very small, and if the trends of technology tell us anything, it is that the future of technology lies in the direction of the very small.

One component our project is to study methods to realize quantum Hall states in cold atoms systems. Quantum Hall states are remarkable quantum states with fractionally charge quasi-particles and fractional statistics. They can also be divided into two classes, those with the so-called “Abelian” statistics, and those with “non-Abelian” statistics. All of them are useful for quantum information storage, and the “non-Abelian” ones are found theoretically to be a robust hardware component for quantum computation – the so-called “fault’ tolerant qubits. The reason that these quasi-particles are so robust in holding quantum information is because of the strongly correlated nature of the quantum Hall state that prevents their decay, unlike the excitations in all other quantum systems. This correlated nature originates from the unique correlated mechanism of particles that rotate relative to one-another with fixed angular momentum, hence giving rise to usual exchange properties of the quasi-particle excitations.

In our proposal, we plan to realize quantum Hall states with bosonic and fermionic atoms using rotating quantum gases. The realization of these states is not to reproduce that known states in condensed matter, but to (i) find ways to locate and manipulate quasi-particles that are necessary for quantum information processing but have so far elude all solid-state experiments, (ii) to realize quantum Hall states (such as those of high spin particles) that are inaccessible to solid-state systems, (iii) to resolve long standing problems in quantum Hall effect such as whether the nu=1/2 and 5/2 fractional quantum Hall state is indeed the Pfaffian state that hosts non-Abelian excitations.

Recently, it is also realized that quantum Hall states can also be realized in a number of other cold atom systems, such as 2D optical lattices and optical ladders with artificial magnetic fluxes. Moreover, recent experiments at the National Institute of Standards and Technology (NIST) by Spielman’s group on the so-called Yang Monopole also suggest the possibility of realizing 4D quantum Hall systems. The fact that experiments in low dimensional space can access the physics in higher dimensional ones is an exciting possibility, and may even be a new avenue for quantum information processing.

In this cycle of NASA-funded research, we have looked into a number other topological matters that are closely related to quantum Hall systems, new physics settings to realize quantum Hall states, as well as mechanisms and protocols to locate and manipulate quasi-particles. The first is to realize the Majorana edge modes in 1D chains with fermions near p-wave resonance. The Majorana edge modes in 1D chains obey non-Abelian statistics like those in the Pfaffian states in quantum Hall systems. The system we considered is a generalization of the Kitaev model with the “p-wave superconductivity” replaced by the fluctuating closed channel bosons. This scheme is much simpler than other schemes to realize Majorana edge modes currently proposed for cold atom systems. We have performed exact calculations to prove that the Majorana edge modes indeed exist in these systems.

Bibliography Type: Description: (Last Updated: 05/19/2020)  Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Mossman ME, Engels P, D'Incao J, Cornell E. "Microgravity Studies of Few-Body Physics." Presented by Maren Mossman at the 33rd Annual Meeting of the American Society for Gravitational and Space Research, Seattle, WA, October 25-28, 2017.

33rd Annual Meeting of the American Society for Gravitational and Space Research, Seattle, WA, October 25-28, 2017. , Oct-2017

Articles in Other Journals or Periodicals Yin XY, Ho TL, Cui X. "Majorana edge state in a number-conserving Fermi gas with tunable p-wave interaction." Cornell University Library. 23 Nov 2017. arXiv:1711.08765 [cond-mat.quant-gas]. Submitted to Physical Review X; see https://arxiv.org/abs/1711.08765 , Nov-2017
Articles in Other Journals or Periodicals Zhang J, Ho TL. "Potential scattering on a spherical surface." Cornell University Library. Submitted on 29 Jul 2017 (v1), last revised 5 Mar 2018 (v2) [cond-mat.quant-gas]. arXiv:1707.09460 [cond-mat.quant-gas] (or arXiv:1707.09460v2 [cond-mat.quant-gas] for this version). Submitted to Journal of Physics B; see https://arxiv.org/abs/1707.09460v2 , Jul-2017
Articles in Other Journals or Periodicals Ho TL, Li C. "The Chern Numbers of Interaction-stretched Monopoles in Spinor Bose Condensates." Cornell University Library. 12 Apr 2017. arXiv:1704.03833 [cond-mat.quant-gas]. Submitted to Physical Review Letters; see https://arxiv.org/abs/1704.03833 , Apr-2017
Articles in Other Journals or Periodicals Wu J, Ho TL, Lu YM. "Symmetry-enforced quantum spin Hall insulators in pi-flux models." Cornell University Library. 14 Mar 2017. arXiv:1703.04776 [cond-mat.quant-gas]. Submitted to Physical Review Letters; see https://arxiv.org/abs/1703.04776 , Mar-2017
Articles in Peer-reviewed Journals Klauss CE, Xie X, Lopez-Abadia C, D'Incao JP, Hadzibabic Z, Jin DS, Cornell EA. "Observation of Efimov molecules created from a resonantly interacting Bose gas." Phys Rev Lett. 2017 Oct 6;119(14):143401. https://doi.org/10.1103/PhysRevLett.119.143401 ; PubMed PMID: 29053296 , Oct-2017
Project Title:  Zero-G Studies of Few-Body and Many-Body Physics Reduce
Images: icon  Fiscal Year: FY 2017 
Division: Physical Sciences 
Research Discipline/Element:
Physical Sciences: FUNDAMENTAL PHYSICS--Fundamental physics 
Start Date: 04/01/2014  
End Date: 04/30/2019  
Task Last Updated: 05/24/2017 
Download report in PDF pdf
Principal Investigator/Affiliation:   Cornell, Eric  Ph.D. / University of Colorado 
Address:  JILA 
440 UCB 
Boulder , CO 80309-0440 
Email: Cornell@jila.colorado.edu 
Phone: 303-492-6281  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of Colorado 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Engels, Peter  Ph.D. Washington State University, Pullman 
Ho, Tin-Lun  Ph.D. Ohio State University 
Key Personnel Changes / Previous PI: May 2017 report: During the reporting period, one of our co-investigators, Deborah Jin, died. Her duties in running the project have been assumed by Eric Cornell, the Principal Investigator. Prof. Jin's laboratory equipment is still in working condition and the supervision of her graduate students is now done by Cornell.
Project Information: Grant/Contract No. JPL 1502690 
Responsible Center: NASA JPL 
Grant Monitor: Israelsson, Ulf  
Center Contact:  
ulf.e.israelsson@jpl.nasa.gov 
Solicitation: 2013 Fundamental Physics NNH13ZTT002N (Cold Atom Laboratory--CAL) 
Grant/Contract No.: JPL 1502690 
Project Type: FLIGHT 
Flight Program: ISS 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Program--Element: FUNDAMENTAL PHYSICS--Fundamental physics 
Task Description: Future advances in both technology and fundamental science will hinge on a better understanding of the weird effects of quantum mechanics on collections of electrons, atoms, molecules, and so on. In some cases, experiments probing this so-called “quantum few-body and many-body physics” can be more readily accomplished in the weightless environment found in an orbiting laboratory. We propose a staged series of experiments, including (1) “first science” experiment, to be performed in the Cold Atom Laboratory (CAL) flying in the International Space Station (ISS) first-generation, to answer a question in few-body quantum physics that can’t be performed in a ground-based laboratory: how universal are the weakly bound clusters of three atoms known as Efimov trimers? In a weightless environment, experiments can be performed at very low densities and temperatures, the perfect conditions for these exotic but fragile quantum states to form. (2) Bose gases with “infinite” interactions. As interactions between atoms become stronger, there is a crossover between gas-phase and liquid behavior. In ultra-cold atoms, the crossover is between a quantum liquid and a quantum gas. (3) Highly rotating quantum gases. Many of the most exotic and unexplored predicted states of matter occur in the presence of very strong magnetic fields, for electrons, or high rates of rotation, for neutral particles. We will explore Quantum Hall physics in highly rotating Bose and Fermi gases. Experiments (2) and (3) will benefit significantly from the longer expansion times and weaker traps possible in weightlessness. Preliminary versions of both experiments will be done in a ground-based laboratory in order to establish the foundation for future flight-based experiments.

Research Impact/Earth Benefits: Physics is the discipline that provides understanding of biology and chemistry at the most microscopic level, and the area within physics most relevant to chemistry and biology is “few-body physics.” It is an often neglected portion of physics, because it is so difficult to do! An important way to make progress is to simplify, simplify, simplify: to come up with model systems in which we can make progress that can later be applied to human-centric disciplines like biology, and develop exotic and useful new materials. A promising way to simplify is to study matter at lower temperature, and lower densities. The Cold-Atom Lab (CAL) flying in the International Space Station (ISS) is where we will reach the lowest possible temperatures, and low densities, to do our studies of simple, yet intricate (think “snowflakes”) clusters of three or four atoms. While CAL is being prepared for flight, we have been doing prefatory experiments and calculations here on Earth. Not at as low temperature, but still cold enough to help us learn things we will need to know to do the space experiments.

Task Progress & Bibliography Information FY2017 
Task Progress: We will be investigating exotic few-body physics, exploiting the specific strengths of NASA’s Cold Atom Laboratory (CAL) onboard the International Space Station (ISS). CAL is a unique experimental platform that utilizes the near-weightlessness onboard the ISS and will make it possible to create atomic clouds that are both very dilute and extremely cold. These clouds are governed by intricate quantum mechanical effects. While Earth-based experiments with quantum gases have led to many revolutionary experiments over the past few years, the microgravity environment in which CAL is placed will allow us to push the boundaries significantly further.

One recent and exciting venture in experiments with ultracold quantum gases is the three-body problem. In 1970, theoretical physicist Vitaly Efimov predicted that, under certain conditions, three atoms can form a bound state even if the attractions between just two atoms are too weak to cause binding. It was not until 2005 that this was first demonstrated in an experiment by a group at the University of Innsbruck. This initiated significant research efforts worldwide both in theoretical and in experimental research. Despite these efforts, further experimental input is needed to assist in theoretical predictions. CAL provides a unique new environment for testing few-body systems in previously inaccessible regimes that are prerequisite for the next generation of Efimov experiments. In preparation for CAL’s launch, our collaboration has modeled actual Efimov experiments to be conducted with CAL.

This past year, we have worked diligently to prepare for initial tests at the Ground Test Bed (GTB) and to prepare our cold atom apparatus at Washington State University (WSU) for corroborative tests with ultracold Potassium-39 clouds. To this goal, we have outlined an experimental plan for work at the GTB that will allow us to test and optimize our planned experimental strategies. This experimental plan will also provide benchmark results that will later be used to verify the proper operation of the CAL apparatus onboard the ISS. At the same time we have made great progress towards the generation of ultracold Potassium-39 clouds at WSU. The motivation behind these experimental efforts at WSU is twofold: First, we try to identify experimental steps that are specific to K-39 and that need to be optimized for the generation of ultracold Potassium-39 clouds with CAL. We have found a number of technical aspects that can affect the operation of a Potassium-39 experiment, and have discussed these aspects with members of the CAL team. A second motivation is the acquisition of control data that will later be needed to interpret the data taken with CAL.

Meanwhile, in the experimental effort at JILA, we have been performing ground-based few-body studies using ultracold atoms. These experiments are meant to compliment the results we anticipate harvesting from the ISS-based Cold Atom Lab in the next two years. We have explored the properties of a potassium/rubidium bose polaron, which is a tiny “snowball” of two or three ultacold atoms right at the conceptual boundary between few- and many-body physics. This work appeared in press in the elite physics journal, Physical Review Letters. We also completed and submitted for publication a ground-based experiment on efimov molecules in Rubidium-85. These efimov molecules were in the first excited state, quite analogous to the efimov molecules we will eventually examine in space, in Potassium-39. Because we were working in the influence of Earth’s gravity, we were unable to access the extreme low-temperature, low-density regime we will achieve in space, and thus we were not able to do the precise comparison we will do next year in space. Finally, we made progress towards completing a precision study on the ground-state efimov trimer in Potassium-39. This will be a control for a similar study done in space.

At the same time, our theoretical wing at Ohio State made progress on few- and many-body calculations of the properties of ultracold gases, with an emphasis on rotating gases, in anticipation of a possible second-generation Cold Atom Laboratory experiment. Our team focuses on “strongly Interacting Bose gas” and “Quantum Hall states of Bose gases.” Bosons are identical particles that tend to occupy the same quantum state. As a result, the ground state of a Bose gas will consist of atoms condensing in the same state, forming a “Bose-Einstein condensate,” thereby magnifying quantum phenomena to a macroscopic scale. It is highly unusual for a Bose system not to have a condensed ground state. Yet an uncondensed ground state can emerge under special circumstances. One example is the strongly interacting Bose gas in low dimensions, where bosons will effectively turn into spinless fermions to avoid interacting with each other. The other example is the fast rotating Bose gas, where the system has many single particle states of the same energy competing for condensation. As a result, the bosons fail to condense into a single state, but form a highly correlated wavefunction (called quantum Hall state) with many novel properties. Our NASA projects are to study the property of a three dimensional Bose gas in the strongly interacting limit, and to realize the quantum Hall state in the fast rotating limit. During last year, we have explored different ways to realize the bosonic quantum Hall states, and to identify their signatures. Achieving bosonic quantum Hall state turns out to be a very challenging task, as this state is strongly competed against by the usual condensed ground state. We noted that it is easier to the create a quantum Hall state of fermions, as their exchange properties (or “Fermi statistics”) favors formation of quantum Hall state. On the other hand, by varying the interactions between fermions, one can associate two fermions of opposite spin into a bosonic molecule, (as demonstrated by Deborah Jin’s group at JILA in 2003 and 2004). In this process, a fermionic quantum Hall state can turn into a bosonic one. The result of this work has been submitted to PRX for publication and is currently under review. This work has led to a number of invited talks at international conferences including the 90th year Cebebration of Fermi’s paper on Fermi statistics at the Galileo Institute for Theoretical Physics in June 2016.

As for identifying the signature with the bosonic quantum Hall state, we have worked out the properties of quantum Hall states in rotating traps with different ellipticity. Due to the intrinsic correlation of that quantum Hall state, the surface contour of the quantum Hall droplet does not follow the equip-potential of the anisotropic trap. Rather, it is an ellipse with a different ellipticity. We are currently writing up this work. Walyon Chen will be giving a talk of this result at the upcoming American Physical Society (APS) March Meeting.

For strongly interacting Bose gas, the experiment of our team is to study the properties of the Bose gas after the interaction between bosons is increased suddenly, a process now referred to as quantum quenching. One key question is how the populations of bosons in different momentum states evolve in time. In order to obtain results that are free from uncontrolled approximations, we have been studying the quantum quenching of one dimensional Bose gas for which exact results can be obtained. The work is in progress.

Bibliography Type: Description: (Last Updated: 05/19/2020)  Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Mossman M, Engels P, D'Incao J, Jin D, Cornell E. "Efimov studies of an ultracold cloud of 39K atoms in microgravity: Numerical modeling and experimental design." 47th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics (DAMOP), Providence, Rhode Island, May 23–27, 2016.

Bulletin of the American Physical Society. 2016;61(8):abstract K1.103. http://meetings.aps.org/Meeting/DAMOP16/Session/K1.103 , May-2016

Articles in Other Journals or Periodicals Ho T-L. "Fusing quantum Hall states in cold atoms." Cornell University Library. 30 Jul 2016. arXiv:1608.00074 [cond-mat.quant-gas]. Submitted to Physical Review X; see https://arxiv.org/abs/1608.00074 , Jul-2016
Articles in Peer-reviewed Journals Hu MG, Van de Graaf MJ, Kedar D, Corson JP, Cornell EA, Jin DS. "Bose polarons in the strongly interacting regime." Phys Rev Lett. 2016 Jul;117(5):055301. https://doi.org/10.1103/PhysRevLett.117.055301 , Jul-2016
Project Title:  Zero-G Studies of Few-Body and Many-Body Physics Reduce
Images: icon  Fiscal Year: FY 2016 
Division: Physical Sciences 
Research Discipline/Element:
Physical Sciences: FUNDAMENTAL PHYSICS--Fundamental physics 
Start Date: 04/01/2014  
End Date: 04/30/2019  
Task Last Updated: 04/02/2016 
Download report in PDF pdf
Principal Investigator/Affiliation:   Cornell, Eric  Ph.D. / University of Colorado 
Address:  JILA 
440 UCB 
Boulder , CO 80309-0440 
Email: Cornell@jila.colorado.edu 
Phone: 303-492-6281  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of Colorado 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Engels, Peter  Ph.D. Washington State University, Pullman 
Ho, Tin-Lun  Ph.D. Ohio State University 
Jin, Deborah  Ph.D. University of Colorado 
Project Information: Grant/Contract No. JPL 1502690 
Responsible Center: NASA JPL 
Grant Monitor: Israelsson, Ulf  
Center Contact:  
ulf.e.israelsson@jpl.nasa.gov 
Solicitation: 2013 Fundamental Physics NNH13ZTT002N (Cold Atom Laboratory--CAL) 
Grant/Contract No.: JPL 1502690 
Project Type: FLIGHT 
Flight Program: ISS 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Program--Element: FUNDAMENTAL PHYSICS--Fundamental physics 
Task Description: Future advances in both technology and fundamental science will hinge on a better understanding of the weird effects of quantum mechanics on collections of electrons, atoms, molecules, and so on. In some cases, experiments probing this so-called “quantum few-body and many-body physics” can be more readily accomplished in the weightless environment found in an orbiting laboratory. We propose a staged series of experiments, including (1) “first science” experiment, to be performed in the Cold Atom Laboratory (CAL) flying in the International Space Station (ISS) first-generation, to answer a question in few-body quantum physics that can’t be performed in a ground-based laboratory: how universal are the weakly bound clusters of three atoms known as Efimov trimers? In a weightless environment, experiments can be performed at very low densities and temperatures, the perfect conditions for these exotic but fragile quantum states to form. (2) Bose gases with “infinite” interactions. As interactions between atoms become stronger, there is a crossover between gas-phase and liquid behavior. In ultra-cold atoms, the crossover is between a quantum liquid and a quantum gas. (3) Highly rotating quantum gases. Many of the most exotic and unexplored predicted states of matter occur in the presence of very strong magnetic fields, for electrons, or high rates of rotation, for neutral particles. We will explore Quantum Hall physics in highly rotating Bose and Fermi gases. Experiments (2) and (3) will benefit significantly from the longer expansion times and weaker traps possible in weightlessness. Preliminary versions of both experiments will be done in a ground-based laboratory in order to establish the foundation for future flight-based experiments.

Research Impact/Earth Benefits: Physics is the discipline that provides understanding of biology and chemistry at the most microscopic level, and the area within physics most relevant to chemistry and biology is “few-body physics.” It is an often neglected portion of physics, because it is so difficult to do! An important way to make progress is to simplify, simplify, simplify: to come up with model systems in which we can make progress that can later be applied to human-centric disciplines like biology, and develop exotic and useful new materials. A promising way to simplify is to study matter at lower temperature, and lower densities. The Cold-Atom Lab (CAL) flying in the International Space Station (ISS) is where we will reach the lowest possible temperatures, and low densities, to do our studies of simple, yet intricate (think “snowflakes”) clusters of three or four atoms. While CAL is being prepared for flight, we have been doing prefatory experiments and calculations here on Earth. Not at as low temperature, but still cold enough to help us learn things we will need to know to do the space experiments.

Task Progress & Bibliography Information FY2016 
Task Progress: We will be investigating exotic few-body physics, exploiting the specific strengths of NASA’s Cold Atom Laboratory (CAL) onboard the International Space Station (ISS). CAL is a unique experimental platform that utilizes the near-weightlessness onboard the ISS and makes it possible to create atomic clouds that are both very dilute and extremely cold. These clouds are governed by intricate quantum mechanical effects. While Earth-based experiments with quantum gases have led to many revolutionary experiments over the past few years, the microgravity environment in which CAL is placed will allow us to push the boundaries significantly further.

One recent and exciting venture in experiments with ultracold quantum gases is the three-body problem. In 1970, theoretical physicist Vitaly Efimov predicted that, under certain conditions, three atoms can form a bound state even if the attractions between just two atoms are too weak to cause binding. It was not until 2005 that this was first demonstrated in an experiment by a group at the University of Innsbruck. This initiated significant research efforts worldwide both in theoretical and in experimental research. Despite these efforts, further experimental input is needed to assist in theoretical predictions. CAL provides a unique new environment for testing few-body systems in previously inaccessible regimes that are prerequisite for the next generation of Efimov experiments. In preparation for CAL’s launch, our collaboration has modeled actual Efimov experiments to be conducted with CAL.

In the past year, our efforts have included numerical and analytic modeling of the CAL lab magnetic field capabilities, and of predicted cold-atom dynamics in those fields. We looked at several different basic experimental strategies, including “delta-kick cooling” and adiabatic expansion. We presented these results at a Scientific Concept Review at JPL (Jet Propulsion Laboratory) in February of 2015. The bottom line result of these efforts is that everything is looking good for a precise measurement of two generations of Efimov states in Potassium-39.

While preparing for experiments in space, we have been doing a number of related experiments in our ground-based laboratories. These experiments are interesting in their own right but they also lay the groundwork for future generation space-based experiments. The most notable result we achieved was the first-ever measurement of the energy and lifetime of a Bose polariton in the strongly interacting regime. Although in our Earth-based project we are not able to reach temperatures as low as those we anticipate reaching in space, we were able to get cold enough to cause individual potassium atom impurities to become entrained in a Bose condensate made of rubidium atoms. The resulting “snow-ball” is a sort of quasi-particle, so-called because it hangs together long enough for us to be able to measure a distinct spectrum for it, much as we could if it were a real particle. In other experimental developments, we found preliminary evidence for the existence of three-body Efimov states in rubidium Bose gas even as the interactions between the atoms become so strong that, at least mathematically, they are “infinite.”

Our experimental work, the preparation for the upcoming ISS measurement, and our ground-based experiments, were complemented by an extensive theoretical efforts. These efforts including work on quantum quenching, quantum turbulence, and the quantum Hall effect. All three topics are candidate projects for future CAL flights.

1. Quantum quenching: we have been studying the quantum quenching in low dimensional systems where it is possible to obtain exact results. We have also noticed that the problem of quantum quenching can be viewed as a process of “inflation,” where the metric of space is rapidly increasing. We have worked out the evolution of density profile and momentum distribution for two and three particle systems, and are trying to the so-called Bethe Ansatz solution to study similar properties of many-particle systems.

2. Quantum turbulence: Recently, the Cambridge experimental group led by Zoran Hadzibabic has performed an experiment to shake a Bose condensate in a box trap vigorously. They found that after some period of shaking, the momentum distribution of the gas develops a power law over a wide range of momentum. (This experiment is currently under review and has not been posted on the preprint archive. We learned about it through communications with the authors.) Turbulence is one of the longest standing problems in physics. It remains unsolved after a century of studies. Once again, cold atom experiments offer a new and flexible platform to study a longstanding problem. Moreover, cold atom experiments also raise new questions. Traditional studies of turbulence have been focusing on velocity-velocity correlation functions, whereas cold atoms experiments force one to consider momentum distributions, which is a more fundamental quantity. We have recently completed a study of the analog of the Cambridge experiment for an ideal gas. The results turn out to be surprisingly rich. We have found the emergence of power law behavior at long times, which is generated by the energy cascade processes driven by the external potential. We are in the process of writing up our results.

3. Quantum Hall states: There are two classes of quantum Hall states, abelian and non-abelian. They are distinguished by the statistics of their quasi particles under exchange. For abelian quantum Hall states, the system acquires a phase factor after the exchange, whereas for non-abelian states, the quasi particles states have internal structures and the exchange process will lead to a change of these internal structures rather than the appearance of a phase factor. In solid-state systems, the descriptions of these quasi-particles are very complicated. Recently, we have found a simple way to describe the wavefunction of the quasi-particles. We are currently trying to design experimental protocols for the exchange processes of these non-abelian quasi-particles so as to reveal their properties.

Bibliography Type: Description: (Last Updated: 05/19/2020)  Show Cumulative Bibliography Listing
 
Abstracts for Journals and Proceedings Klauss C, Xie X, Jin D, Cornell E. "Universal Dynamics in a Unitary Bose Gas." Contributed talk by C. Klauss. 46th Annual Meeting of the APS Division of Atomic, Molecular and Optical Physics, Columbus, OH, June 8-12, 2015.

Bulletin of the American Physical Society 2015 Jun;60(7):Abstract ID: BAPS.2015.DAMOP.G3.3. http://meetings.aps.org/link/BAPS.2015.DAMOP.G3.3 , Jun-2015

Abstracts for Journals and Proceedings Jin D. "AMO." Invited talk. Department Seminar, University of British Columbia, Canada, November 19, 2015.

Department Seminar, University of British Columbia, Canada, November 19, 2015. , Nov-2015

Abstracts for Journals and Proceedings Jin D. "Bose polarons in the strongly interacting regime." Invited talk by D. Jin. Presented at Bose Einstein Condensation 2015, Sant Feliu, Spain, September 5-11, 2015.

Bose Einstein Condensation 2015, Sant Feliu, Spain, September 5-11, 2015. , Sep-2015

Abstracts for Journals and Proceedings Jin D. "A strongly interacting Bose-Einstein condensate." Invited talk. Fundamental Optical Processes in Semiconductors (FOPS) 2015, Breckenridge, CO, August 2-7 2015.

Fundamental Optical Processes in Semiconductors (FOPS) 2015, Breckenridge, CO, August 2-7 2015. , Aug-2015

Abstracts for Journals and Proceedings Jin D. "Fun with Ultracold Atoms." Invited talk. 40th Annual Donald Hamilton Lecture, Princeton University, April 30, 2015.

40th Annual Donald Hamilton Lecture, Princeton University, April 30, 2015. , Apr-2015

Abstracts for Journals and Proceedings Jin D. "Ultracold Atoms and Molecules." Invited talk. Presented at the JASON Spring Meeting, McLean, VA, April 25, 2015.

JASON Spring Meeting, McLean, VA, April 25, 2015. , Apr-2015

Abstracts for Journals and Proceedings Cornell E. "Experiments on Degenerate Bose Gases with Unitary Interactions." Invited talk. National Tsing Hua University, Singapore, June 30, 2015.

National Tsing Hua University, Singapore, June 30, 2015. , Jun-2015

Abstracts for Journals and Proceedings Cornell E. "Experiments on Degenerate Bose Gases with Unitary Interactions." Invited talk. 2015 Taiwan International Symposium on Contemporary Atomic and Optical Physics, Taiwan, July 9-10, 2015.

2015 Taiwan International Symposium on Contemporary Atomic and Optical Physics, Taiwan, July 9-10, 2015. , Jul-2015

Abstracts for Journals and Proceedings Ho T-L. "Quantum Gases in Curved Surfaces" Invited talk. Presented at the Workshop on Frontiers in Quantum Gases, Institute of Nuclear Studies, University of Washington, Seattle, May 22, 2015.

Workshop on Frontiers in Quantum Gases, Institute of Nuclear Studies, University of Washington, Seattle, May 22, 2015. , May-2015

Abstracts for Journals and Proceedings Ho T-L. "Quantum Gases in Curved Surfaces." Invited talk. Presented at the 2015 Taiwan International Symposium on Contemporary Atomic and Optical 30 years anniversary of IAMP, Taipei, July 8-10, 2015.

2015 Taiwan International Symposium on Contemporary Atomic and Optical 30 years anniversary of IAMP, Taipei, July 8-10, 2015. , Jul-2015

Abstracts for Journals and Proceedings Ho T-L. "Quantum Gases in Curved Surfaces." Invited talk. Presented at the XVIII Progress in Many-Body Theory Conference, Niagara Falls, July 8-10, 2015.

XVIII Progress in Many-Body Theory conference, Niagara Falls, July 8-10, 2015. , Jul-2015

Abstracts for Journals and Proceedings Ho T-L. "Challenges in Cold Atom Physics." Invited talk. Presented at the NSF Workshop on the Grand Challenges in Quantum Fluids and Solids, University of Buffalo, August 7-9, 2015.

NSF Workshop on the Grand Challenges in Quantum Fluids and Solids, University of Buffalo, August 7-9, 2015. , Aug-2015

Abstracts for Journals and Proceedings Ho T-L. "Many-Body Localization in Cold Atom Systems." Invited talk. Quantum Fluids from nk to TeV: An 80th Birthday Symposium in Honor of Gordon Baym, Urbana, IL, October 16-17, 2015.

Quantum Fluids from nk to TeV: An 80th Birthday Symposium in Honor of Gordon Baym, Urbana, IL, October 16-17, 2015. , Oct-2015

Abstracts for Journals and Proceedings Ho T-L. "Quantum Turbulence." Invited talk. Presented at the MURI Workshop on Non-equilibrium Physics, University of Berkeley, January 12, 2016.

MURI Workshop on Non-equilibrium Physics, University of Berkeley, January 12, 2016. , Jan-2016

Abstracts for Journals and Proceedings Ho T-L. "Quantum Gases in Curved Surfaces." Invited talk. Colloquium presented at the University of Chicago, January 14, 2016.

Colloquium presented at the University of Chicago, January 14, 2016. , Jan-2016

Abstracts for Journals and Proceedings Ho T-L. "Quantum Turbulence." Invited talk. Presented at the University of Illinois at Urbana-Champaign, March 7, 2016.

Invited talk at University of Illinois at Urbana-Champaign, March 7, 2016. , Mar-2016

Abstracts for Journals and Proceedings Ho T-L. "Quantum Turbulence." Invited talk. Presented at the Institute of Advanced Studies, Tsinghua University, Beijing, March 17, 2016.

Institute of Advanced Studies, Tsinghua University, Beijing, March 17, 2016. , Mar-2016

Abstracts for Journals and Proceedings Ho T-L. "Non-abelian Statistics with Cold Atoms." Invited talk. Presented at the International Conference on Fermi Gases, in Celebration of the 90th Anniversary of Fermi' paper on Fermi statistics, Florence, Italy, March 21, 2016.

International Conference on Fermi Gases, in Celebration of the 90th Anniversary of Fermi' paper on Fermi statistics, Florence, Italy, March 21, 2016. , Mar-2016

Abstracts for Journals and Proceedings Ho T-L. "Dynamics of quantum gases in stretched spacetime." Invited talk. Presented at the Institute of Advanced Studies, Tsinghua University, Beijing, March 25, 2016.

Institute of Advanced Studies, Tsinghua University, Beijing, March 25, 2016. , Mar-2016

Articles in Peer-reviewed Journals Zhu Z, Weng Z-Y, Ho, T-L. "Spin and charge modulations in a single hole doped Hubbard ladder: verification with optical lattice experiments." Physical Review A. 2016 Mar;93(3):033614. http://dx.doi.org/10.1103/PhysRevA.93.033614 , Mar-2016
Articles in Peer-reviewed Journals Ho T-L, Huang B. "Spinor condensates on a cylindrical surface in synthetic gauge fields." Physical Review Letters. 2015 Oct 9;115(15):155304. PubMed PMID: 26550734 ; http://dx.doi.org/10.1103/PhysRevLett.115.155304 , Oct-2015
Articles in Peer-reviewed Journals Ho T-L, Huang B. "Local spin structure of large spin fermions." Physical Review A. 2015 Apr;91(4):043601. http://dx.doi.org/10.1103/PhysRevA.91.043601 , Apr-2015
Project Title:  Zero-G Studies of Few-Body and Many-Body Physics Reduce
Images: icon  Fiscal Year: FY 2015 
Division: Physical Sciences 
Research Discipline/Element:
Physical Sciences: FUNDAMENTAL PHYSICS--Fundamental physics 
Start Date: 04/01/2014  
End Date: 04/30/2019  
Task Last Updated: 01/29/2015 
Download report in PDF pdf
Principal Investigator/Affiliation:   Cornell, Eric  Ph.D. / University of Colorado 
Address:  JILA 
440 UCB 
Boulder , CO 80309-0440 
Email: Cornell@jila.colorado.edu 
Phone: 303-492-6281  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of Colorado 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Engels, Peter  Ph.D. Washington State University, Pullman 
Ho, Tin-Lun  Ph.D. Ohio State University 
Jin, Deborah  Ph.D. University of Colorado 
Project Information: Grant/Contract No. JPL 1502690 
Responsible Center: NASA JPL 
Grant Monitor: Israelsson, Ulf  
Center Contact:  
ulf.e.israelsson@jpl.nasa.gov 
Solicitation: 2013 Fundamental Physics NNH13ZTT002N (Cold Atom Laboratory--CAL) 
Grant/Contract No.: JPL 1502690 
Project Type: FLIGHT 
Flight Program: ISS 
No. of Post Docs:
No. of PhD Candidates:
No. of Master's Candidates:  
No. of Bachelor's Candidates:
No. of PhD Degrees:
No. of Master's Degrees:
No. of Bachelor's Degrees:
Program--Element: FUNDAMENTAL PHYSICS--Fundamental physics 
Task Description: Future advances in both technology and fundamental science will hinge on a better understanding of the weird effects of quantum mechanics on collections of electrons, atoms, molecules, and so on. In some cases, experiments probing this so-called “quantum few-body and many-body physics” can be more readily accomplished in the weightless environment found in an orbiting laboratory. We propose a staged series of experiments, including (1) “first science” experiment, to be performed in the Cold Atom Laboratory (CAL) flying in the International Space Station (ISS) first-generation, to answer a question in few-body quantum physics that can’t be performed in a ground-based laboratory: how universal are the weakly bound clusters of three atoms known as Efimov trimers? In a weightless environment, experiments can be performed at very low densities and temperatures, the perfect conditions for these exotic but fragile quantum states to form. (2) Bose gases with “infinite” interactions. As interactions between atoms become stronger, there is a crossover between gas-phase and liquid behavior. In ultra-cold atoms, the crossover is between a quantum liquid and a quantum gas. (3) Highly rotating quantum gases. Many of the most exotic and unexplored predicted states of matter occur in the presence of very strong magnetic fields, for electrons, or high rates of rotation, for neutral particles. We will explore Quantum Hall physics in highly rotating Bose and Fermi gases. Experiments (2) and (3) will benefit significantly from the longer expansion times and weaker traps possible in weightlessness. Preliminary versions of both experiments will be done in a ground-based laboratory in order to establish the foundation for future flight-based experiments.

Research Impact/Earth Benefits: Physics is the discipline that provides understanding of biology and chemistry at the most microscopic level, and the area within physics most relevant to chemistry and biology is “few-body physics.” It is an often neglected portion of physics, because it is so difficult to do! An important way to make progress is to simplify, simplify, simplify: to come up with model systems in which we can make progress that can later be applied to human-centric disciplines like biology, and develop exotic and useful new materials. A promising way to simplify is to study matter at lower temperature, and lower densities. The Cold-Atom Lab (CAL) flying in the International Space Station (ISS) is where we will reach the lowest possible temperatures, and low densities, to do our studies of simple, yet intricate (think “snowflakes”) clusters of three or four atoms. While CAL is being prepared for flight, we have been doing prefatory experiments and calculations here on Earth. Not at as low temperature, but still cold enough to help us learn things we will need to know to do the space experiments.

Task Progress & Bibliography Information FY2015 
Task Progress: The goal of this project is the investigation of exotic few-body physics, exploiting the specific strengths of NASA’s Cold Atom Laboratory (CAL) onboard the International Space Station (ISS). CAL is a unique experimental platform because the near weightlessness onboard the ISS makes it possible to create atomic clouds that are, at the same time, very dilute and extremely cold. These clouds are governed by intricate quantum mechanical effects. While Earth-based experiments with quantum gases have led to many revolutionary experiments over the past few years, the microgravity environment in which CAL is placed will allow us to push the boundaries significantly further.

One recent and exciting venture in experiments with ultracold quantum gases has been the three-body problem. In 1970, theoretical physicist Vitaly Efimov predicted that, under certain conditions, three atoms can form a bound state even if the attractions between just two atoms are too weak to cause binding. It was not until 2005 that this was first demonstrated in an experiment by a group at the University of Innsbruck. This initiated significant research efforts worldwide both in theoretical and in experimental research. Despite these efforts, further experimental input is needed to assist in theoretical predictions, which fluctuate widely. CAL provides a unique new environment for testing few-body systems in new and previously inaccessible regimes that are prerequisite for the next generation of Efimov experiments. In preparation for CAL’s launch in 2016, our work-to-date for this project has involved analytic calculations and numerical modeling of actual Efimov experiments to be conducted with CAL.

We are currently conducting numerical analyses addressing the question of how we can attain optimum data while keeping the complexity of the experiment low. To this goal, our numerical calculations simulate exactly what the cloud of atoms will act like in a micro-gravity environment by using actual design parameters of the CAL facility. The planned experiments begin with an ultracold cloud of atoms trapped by a suitably tailored magnetic field. This cloud is prepared using evaporative cooling techniques similar to those used in Earth based experiments. From there, different pathways can be followed to reach the extreme regimes required for next-generation Efimov experiments. First, one can slowly ramp down the trapping confinement, during which the cloud cools in process called adiabatic cooling. Alternatively, one can suddenly turn the trapping confinement off so that the cloud expands ballistically. A subsequent “magnetic field delta-kick,” during which the trapping confinement is switched on again for a very brief period of time, then stops the ballistic expansion and leads to a super cooled cloud. A combination of these two techniques is also possible. In our thermodynamic calculations we are assessing the efficiencies of these methods and matching them to the experimental design parameters of CAL. The final cooling procedure establishes clouds that are very dilute and ultracold, with temperatures on the order of 100pK, the perfect regime for Efimov studies. After this, we plan to apply a homogeneous magnetic field for a set time. This homogeneous field determines how strongly atoms interact with each other, through an effect called Fano-Feshbach resonance. We then will observe how the cloud loses atoms over time as collisions in the cloud occur. When plotted as a function of the atomic interaction strength (determined by the applied homogeneous magnetic field), these losses contain signatures of the Efimov states under investigation.

The research conducted in the frame of this project lays the groundwork for future investigations of few-body physics using NASA’s planned CAL facility onboard the ISS. While CAL is currently under construction at JPL, our modeling, based on actual design parameters of CAL, paves the way for the next-generation Efimov experiments. We have identified successful pathways to generate atomic clouds with sufficiently low density and temperature and have determined realistic parameters to be used in these studies.

To develop the intricate patterns of atoms we want to study, we need low temperatures, yes, but also we need to get the atoms to clump together in interesting ways. Towards this end, and in parallel with our work on Efimov resonances, we are spinning the cloud of atoms at ever higher rates. The individual atoms, like strands of wool being spun into yarn, become increasingly more entangled. This year we have succeeded in spinning atoms rapidly in a novel atomic trap, a sort of bowl for atoms constructed of laser beams. Our hope is to do a similar experiment in a second-generation Cold Atom Laboratory, on the ISS. In other progress this year, we have improved our ability to take pictures of the cold atoms. Going into this past year, if two clumps of atoms were closer together than about four ten thousandths of an inch, they would appear us a single blurry clump. Now we can see patterns of atoms that are two times smaller than before. This will help us better understand what’s going on at extremely low temperatures.

To interpret our results from CAL, both the Efimov state work and the high-rotation work, we will need to have extensive theoretical understanding. We have been making progress in this area over the last year.

Together with Dr. Ran Qi (NIST), we have studied the quantum quenching of two and three particle systems in a trap. Specially, we study the time evolution of the system after the interaction between particles suddenly jumped from being weakly repulsive to being strongly repulsive. We have investigated this evolution for different kind of confining potential. We have completed the study for the two-particle case, and is in the process of studying the three particle case. The study of the two-particle case reveals a universal structure of the time evolution. The study of the three-particle case will illustrate the relative role between two- and three-particle contributions in quantum quenching. Our long term goal is to use the insight from a few body study to construct a general description (like that renormalization group) for systems with a large number of particles, which will form a solution of this class of long-standing non-equilibrium problems.

Theoretically, it is known that a rotating quantum gas will reach the so-called quantum Hall state when it gains sufficiently large angular momentum. A necessary condition to realize quantum Hall states is to reach the fast rotating regime where the energy levels of the particles are organized into almost degenerate levels (called Landau levels). This regime has been achieved by the lead P.I. (E. Cornell) of our team. The next step is to increase the angular momentum further to reach the quantum Hall state. For Bose gases, this turns out to be a difficult step as Bose-Einstein condensation competes strongly with the formation of quantum Hall states. In contrast, it is much easier for Fermi gases to go into quantum Hall states, since their formations are helped by Fermi statistics. On the other hand, another member of our team (D. Jin) has pioneered the technique of associating fermion pairs into bosons by changing the interaction of the system, which can be achieved by simply varying an external magnetic field. This then create a new path for us to achieve the bosonic quantum Hall states. One can first produce a fermionic quantum Hall state, and then associate the fermionic quantum Hall states into bosonic ones by changing the interaction between particles. At present, our theory group, led by T.-L. Ho, has been performing theoretical studies of this association process, as well as methods to identify the presence of quantum Hall states. We have demonstrated the success forming bosonic quantum Hall states in this association process. We are now trying to extend the study to systems with larger number of particles. Together with our students, we have also shown that the presence of quantum Hall states can be easily identified through their density profiles and local density fluctuations.

Bibliography Type: Description: (Last Updated: 05/19/2020)  Show Cumulative Bibliography Listing
 
 None in FY 2015
Project Title:  Zero-G Studies of Few-Body and Many-Body Physics Reduce
Images: icon  Fiscal Year: FY 2014 
Division: Physical Sciences 
Research Discipline/Element:
Physical Sciences: FUNDAMENTAL PHYSICS--Fundamental physics 
Start Date: 04/01/2014  
End Date: 04/30/2019  
Task Last Updated: 07/25/2014 
Download report in PDF pdf
Principal Investigator/Affiliation:   Cornell, Eric  Ph.D. / University of Colorado 
Address:  JILA 
440 UCB 
Boulder , CO 80309-0440 
Email: Cornell@jila.colorado.edu 
Phone: 303-492-6281  
Congressional District:
Web:  
Organization Type: UNIVERSITY 
Organization Name: University of Colorado 
Joint Agency:  
Comments:  
Co-Investigator(s)
Affiliation: 
Engels, Peter  Ph.D. Washington State University, Pullman 
Ho, Tin-Lun  Ph.D. Ohio State University 
Jin, Deborah  Ph.D. University of Colorado 
Project Information: Grant/Contract No. JPL 1502690 
Responsible Center: NASA JPL 
Grant Monitor: Israelsson, Ulf  
Center Contact:  
ulf.e.israelsson@jpl.nasa.gov 
Solicitation: 2013 Fundamental Physics NNH13ZTT002N (Cold Atom Laboratory--CAL) 
Grant/Contract No.: JPL 1502690 
Project Type: FLIGHT 
Flight Program: ISS 
No. of Post Docs:  
No. of PhD Candidates:  
No. of Master's Candidates:  
No. of Bachelor's Candidates:  
No. of PhD Degrees:  
No. of Master's Degrees:  
No. of Bachelor's Degrees:  
Program--Element: FUNDAMENTAL PHYSICS--Fundamental physics 
Task Description: Future advances in both technology and fundamental science will hinge on a better understanding of the weird effects of quantum mechanics on collections of electrons, atoms, molecules, and so on. In some cases, experiments probing this so-called “quantum few-body and many-body physics” can be more readily accomplished in the weightless environment found in an orbiting laboratory. We propose a staged series of experiments, including (1) “first science” experiment, to be performed in the Cold Atom Laboratory (CAL) flying in the International Space Station (ISS) first-generation, to answer a question in few-body quantum physics that can’t be performed in a ground-based laboratory: how universal are the weakly bound clusters of three atoms known as Efimov trimers? In a weightless environment, experiments can be performed at very low densities and temperatures, the perfect conditions for these exotic but fragile quantum states to form. (2) Bose gases with “infinite” interactions. As interactions between atoms become stronger, there is a crossover between gas-phase and liquid behavior. In ultra-cold atoms, the crossover is between a quantum liquid and a quantum gas. (3) Highly rotating quantum gases. Many of the most exotic and unexplored predicted states of matter occur in the presence of very strong magnetic fields, for electrons, or high rates of rotation, for neutral particles. We will explore Quantum Hall physics in highly rotating Bose and Fermi gases. Experiments (2) and (3) will benefit significantly from the longer expansion times and weaker traps possible in weightlessness. Preliminary versions of both experiments will be done in a ground-based laboratory in order to establish the foundation for future flight-based experiments.

Research Impact/Earth Benefits: 0

Task Progress & Bibliography Information FY2014 
Task Progress: New project for FY2014.

Bibliography Type: Description: (Last Updated: 05/19/2020)  Show Cumulative Bibliography Listing
 
 None in FY 2014