NOTE: End date changed to 9/27/2024 per U. Israelsson/JPL (Ed., 10/20/21)

NOTE: Extended to 3/31/2023 per U. Israelsson/JPL (Ed., 7/10/19)

NOTE: Extended to 4/30/2019 per U. Israelsson/JPL (Ed., 12/14/17)

We represent a research consortium of senior people, all pioneers in Bose-Einstein condensation, atom optics, atom interferometry, and related areas, with experience with NASA’s program on fundamental research in microgravity. The Consortium’s work is described in the context of four Tasks.

Task 1: Advanced Clocks in Space and Time Transfer

Task 2: Maturing and Advancing Atom Interferometer Technology for Space

Task 3: Precision Atom Interferometric Measurement in Space

Task 4: Strategies for the Frontier of Ultracold Atoms in Space.

The Consortium is: N. P. Bigelow, M. Kasevick, W. Ketterle, M. Lukin, H. Müller, W. D. Phillips, D. Pritchard, D. Stamper-Kurn, V. Vuletic, and J. Ye.

We have established a cooperation with German Scientists: C. Braxmaier, W. Ertmer, C. Lämmerzahl, A. Peters, E. M. Rasel, and W. P. Schleich. In forming this Consortium, we have several aims: (1) to, in one consolidated move, provide NASA with a community of talented and respected researchers who are committed to developing well thought out, highly impactful precision, quantum gas and atomic physics space experiments; (2) to support several first-class experimental efforts with significant potential to impact NASA interests and specifically to impact future flight experiments or indeed to become flight definition experiments; and (3) to provide intellectually compelling strategies that will impact future generations of flight experiments, aboard the International Space Station (ISS) and beyond. This consortium will provide NASA with a far larger return than could be expected from a series of individual projects. In part this is because of the natural synergies among the interests and expertise of the Consortium members. In part this is because the membership is meeting regularly in person and via teleconference in order to create and refine ideas beyond the work described at the formation of the consortium, challenging each other to advance only the most excellent projects to NASA.

The interests and expertise of the Consortium represent two of the four Thrusts identified in a recent National Research Council (NRC) report and the current NASA Research Announcement: (1) Precision Measurement of Fundamental Forces and Symmetries and (2) Quantum Gasses. In the present proposal we choose to focus on two specific areas: ultra-performance clocks and clock networks and atom interferometers (including those using degenerate quantum gasses). We have developed a cooperation plan with leading German expert scientists involved with DLR (German Space Agency) sponsored work in Bremen who are collaborators on this proposal.

Berkeley and Stanford lead Tasks 2 and 3.

MIT, U.C./JILA, and Harvard lead Task 1.

U. Md., Rochester, and MIT lead Task 4.

Members of the Consortium can and often will contribute to all four tasks with priorities being set by the lead institutions.

Significant progress has been made on atomic interferometry and atomic clocks in terrestrial experiments. The work has long-term impact for fundamental science, navigation technologies, and global clock synchronization. Clocks are vital to navigation, communication, and security.

ATOM INTERFEROMETRY

We have pushed atom interferometry for space applications forward in many ways:

1. We have shown that atom interferometry can detect dark-energy scalar fields with unprecedented sensitivity. There is a chance to cover all the relevant parameter space so as to detect them or to rule them out once and for all. This work has been published in Science, Nature Physics, and Physical Review D.

2. We have demonstrated a theoretically predicted, but never observed, attractive force on atoms from blackbody radiation. It is an important limitation that has to be taken into account in the design of atomic-physics space missions.

3. We have pushed forward the accuracy of atom interferometry for measuring the fine structure constant, which has resulted in a measurement of this constant with an accuracy about three times better than the best previous one. The agreement of this measurement with others sets very strong constraints on hypothesized particles from the dark sector, such as dark photons.

4. We have developed atom interferometry with "lukewarm" lithium atoms, opening up the possibility to do interferometry with a much wider class of atoms than available previously.

We will continue to develop atom interferometry for demonstrating the gravitational Aharonov-Bohm effect, and measuring fundamental constants very precisely. We will also work with the Bose-Einstein Condensate Cold Atom Laboratory (BECCAL) science definition team and other teams to identify future targets for spaceborne fundamental physics. The interferometry work has several main thrusts. In the first thrust, we have been investigating how spaceborne atom interferometry can probe models for dark matter and dark energy. This has resulted in experimental demonstrations of such tests for so-called chameleon and symmetron models, and theoretical studies on how to make detailed predictions of the putative signals. In the second thrust, we have developed strategies to overcome systematic effects in atom interferometers that use Bragg diffraction, as the one planned for the Cold Atom lab. In the third, we have developed specific plans for spaceborne atom interferometry. We have collaborated with the German team Document for atom interferometry on the Cold Atom Lab and BECCAL. Plans include demonstrating long coherence times thanks to microgravity, tests of the equivalence principle, and searches for dark-energy candidates. They have also collaborated with Nan Yu (Jet Propulsion Laboratory-JPL) on a concept study QTEST (Quantum test of the Equivalence Principle and Spacer-Time) for testing the equivalence principle in space.

CLOCKS AND QUANTUM SENSORS & TECHNOLOGIES

We have demonstrated the first direct optical cooling to Bose-Einstein condensation, without any evaporative cooling. This has promising impact of simplifying spaceborne experiments. The Bose-Einstein condensation by direct optical cooling was achieved for small ensembles of ~1000 atom. We will attempt to make substantially larger condensates with the same method by using a more powerful trapping laser.

We have been working on spin squeezing in the optical-transition clock with trapped ytterbium atoms. By implementing both frequency and intensity feedback loops for the magical wavelength trap inside an optical cavity, we have now lengthened the trap lifetime for the Yb sample from 200 ms to 2 seconds. We have also started non-destructive state-dependent measurements for spin squeezing by observing the light transmitted through the cavity, and we can already more than resolve the shot-noise limit.

In the Rb experiment, we are working towards using Rydberg states for increasing the light-atom interaction in cavity QED. We have frequency-stabilized the control laser coupling the P state to high-lying Rydberg states.

We have demonstrated a new optical lattice clock configuration using a three-dimensional optical lattice, leading to measurement precision in the 19th decimal place. We have also demonstrated another record-breaking performance on stable lasers, with the narrowest laser linewidth at 10 mHz. We will perform a clock comparison between this JILA Sr clock and the NIST (National Institute of Standards & Technology) Yb clock and Search for ultralight dark matter by comparing the Sr transition frequency with the resonance frequency of a crystalline cavity.

2022 Update:

Our team aims to study: o The realization of a space atom laser o Precision atom interferometry in space o The investigation and manipulation of quantum gas sample control including deep cooling, condensate mixture phases, and precision motional control

Relevance: Potential for significant scientific advancement from interferometric tests of the equivalence principle with quantum test masses and pushing the limits of the standard model. Space atom laser provides truly novel investigations of the wave-like nature of matter. Varied experiments of the investigation and manipulation of quantum gases (both single-species and dual-species) mature the technology of quantum gases and provide first of its kind investigations for interacting quantum gases in space.

Work completed: Single species Rubidium (Rb) atom interferometry (AI) demonstrated Shear-wave AI with single species demonstrated Quantum gas control: unprecedented cooling to approximately <50pK Remaining science investigations (target to complete by 03/2024): Quantum sensor: AI-based magnetometer and magneto-gradiometer Space atom laser (preliminary) AI-based ISS rotation measurement (preliminary) AI-based ISS boost accelerometer Dual-species AI based equivalence principle test (proof of principle) Rubidium and Potassium (Rb and K) quantum gas control Quantum mixture studies Remaining science investigations (needs capabilities beyond Science Module 3/SM3): Space atom laser (needs low power radio frequency/RF to achieve low-temperature outcoupling) AI-based ISS rotation measurement (greater atom numbers than possible in SM3 and enhanced AI wavefront necessary) AI-based measurements for Dark Energy Detection (proof of principle, better AI Bragg beam wavefront likely necessary) Quantum mixture studies (greater atoms than possible in SM3 likely necessary)

Assessment of most promising uncompleted work: Dual-species AI-based equivalence principle test (preliminary) Space atom laser with ultra-low energy outcoupling (assuming upgrade for low-energy RF can be implemented) Quantum mixture studies with Rubidium and Potassium (assuming greater atom numbers are achievable with both Rubidium and Potassium)

NOTE: Extended to 3/31/2023 per U. Israelsson/JPL (Ed., 7/10/19)

NOTE: Extended to 4/30/2019 per U. Israelsson/JPL (Ed., 12/14/17)

We represent a research consortium of senior people, all pioneers in Bose-Einstein condensation, atom optics, atom interferometry, and related areas, with experience with NASA’s program on fundamental research in microgravity. The Consortium’s work is described in the context of four Tasks.

Task 1: Advanced Clocks in Space and Time Transfer

Task 2: Maturing and Advancing Atom Interferometer Technology for Space

Task 3: Precision Atom Interferometric Measurement in Space

Task 4: Strategies for the Frontier of Ultracold Atoms in Space.

The Consortium is: N. P. Bigelow, M. Kasevick, W. Ketterle, M. Lukin, H. Müller, W. D. Phillips, D. Pritchard, D. Stamper-Kurn, V. Vuletic, and J. Ye.

We have established a cooperation with German Scientists: C. Braxmaier, W. Ertmer, C. Lämmerzahl, A. Peters, E. M. Rasel, and W. P. Schleich. In forming this Consortium, we have several aims: (1) to, in one consolidated move, provide NASA with a community of talented and respected researchers who are committed to developing well thought out, highly impactful precision, quantum gas and atomic physics space experiments; (2) to support several first-class experimental efforts with significant potential to impact NASA interests and specifically to impact future flight experiments or indeed to become flight definition experiments; and (3) to provide intellectually compelling strategies that will impact future generations of flight experiments, aboard the International Space Station (ISS) and beyond. This consortium will provide NASA with a far larger return than could be expected from a series of individual projects. In part this is because of the natural synergies among the interests and expertise of the Consortium members. In part this is because the membership is meeting regularly in person and via teleconference in order to create and refine ideas beyond the work described at the formation of the consortium, challenging each other to advance only the most excellent projects to NASA.

The interests and expertise of the Consortium represent two of the four Thrusts identified in a recent National Research Council (NRC) report and the current NASA Research Announcement: (1) Precision Measurement of Fundamental Forces and Symmetries and (2) Quantum Gasses. In the present proposal we choose to focus on two specific areas: ultra-performance clocks and clock networks and atom interferometers (including those using degenerate quantum gasses). We have developed a cooperation plan with leading German expert scientists involved with DLR (German Space Agency) sponsored work in Bremen who are collaborators on this proposal.

Berkeley and Stanford lead Tasks 2 and 3.

MIT, U.C./JILA, and Harvard lead Task 1.

U. Md., Rochester, and MIT lead Task 4.

Members of the Consortium can and often will contribute to all four tasks with priorities being set by the lead institutions.

Significant progress has been made on atomic interferometry and atomic clocks in terrestrial experiments. The work has long-term impact for fundamental science, navigation technologies, and global clock synchronization. Clocks are vital to navigation, communication, and security.

ATOM INTERFEROMETRY

We have pushed atom interferometry for space applications forward in many ways:

1. We have shown that atom interferometry can detect dark-energy scalar fields with unprecedented sensitivity. There is a chance to cover all the relevant parameter space so as to detect them or to rule them out once and for all. This work has been published in Science, Nature Physics, and Physical Review D.

2. We have demonstrated a theoretically predicted, but never observed, attractive force on atoms from blackbody radiation. It is an important limitation that has to be taken into account in the design of atomic-physics space missions.

3. We have pushed forward the accuracy of atom interferometry for measuring the fine structure constant, which has resulted in a measurement of this constant with an accuracy about three times better than the best previous one. The agreement of this measurement with others sets very strong constraints on hypothesized particles from the dark sector, such as dark photons.

4. We have developed atom interferometry with "lukewarm" lithium atoms, opening up the possibility to do interferometry with a much wider class of atoms than available previously.

We will continue to develop atom interferometry for demonstrating the gravitational Aharonov-Bohm effect, and measuring fundamental constants very precisely. We will also work with the Bose-Einstein Condensate Cold Atom Laboratory (BECCAL) science definition team and other teams to identify future targets for spaceborne fundamental physics. The interferometry work has several main thrusts. In the first thrust, we have been investigating how spaceborne atom interferometry can probe models for dark matter and dark energy. This has resulted in experimental demonstrations of such tests for so-called chameleon and symmetron models, and theoretical studies on how to make detailed predictions of the putative signals. In the second thrust, we have developed strategies to overcome systematic effects in atom interferometers that use Bragg diffraction, as the one planned for the Cold Atom lab. In the third, we have developed specific plans for spaceborne atom interferometry. We have collaborated with the German team Document for atom interferometry on the Cold Atom Lab and BECCAL. Plans include demonstrating long coherence times thanks to microgravity, tests of the equivalence principle, and searches for dark-energy candidates. They have also collaborated with Nan Yu (Jet Propulsion Laboratory-JPL) on a concept study QTEST (Quantum test of the Equivalence Principle and Spacer-Time) for testing the equivalence principle in space.

CLOCKS AND QUANTUM SENSORS & TECHNOLOGIES

We have demonstrated the first direct optical cooling to Bose-Einstein condensation, without any evaporative cooling. This has promising impact of simplifying spaceborne experiments. The Bose-Einstein condensation by direct optical cooling was achieved for small ensembles of ~1000 atom. We will attempt to make substantially larger condensates with the same method by using a more powerful trapping laser.

We have been working on spin squeezing in the optical-transition clock with trapped ytterbium atoms. By implementing both frequency and intensity feedback loops for the magical wavelength trap inside an optical cavity, we have now lengthened the trap lifetime for the Yb sample from 200 ms to 2 seconds. We have also started non-destructive state-dependent measurements for spin squeezing by observing the light transmitted through the cavity, and we can already more than resolve the shot-noise limit.

In the Rb experiment, we are working towards using Rydberg states for increasing the light-atom interaction in cavity QED. We have frequency-stabilized the control laser coupling the P state to high-lying Rydberg states.

We have demonstrated a new optical lattice clock configuration using a three-dimensional optical lattice, leading to measurement precision in the 19th decimal place. We have also demonstrated another record-breaking performance on stable lasers, with the narrowest laser linewidth at 10 mHz. We will perform a clock comparison between this JILA Sr clock and the NIST (National Institute of Standards & Technology) Yb clock and Search for ultralight dark matter by comparing the Sr transition frequency with the resonance frequency of a crystalline cavity.

ATOM INTERFEROMETRY

We have pushed atom interferometry for space applications forward in many ways:

1. We have shown that atom interferometry can detect dark-energy scalar fields with unprecedented sensitivity. There is a chance to cover all the relevant parameter space so as to detect them or to rule them out once and for all. This work has been published in Science, Nature Physics, and Physical Review D.

2. We have demonstrated a theoretically predicted, but never observed, attractive force on atoms from blackbody radiation. It is an important limitation that has to be taken into account in the design of atomic-physics space missions.

3. We have pushed forward the accuracy of atom interferometry for measuring the fine structure constant, which has resulted in a measurement of this constant with an accuracy about three times better than the best previous one. The agreement of this measurement with others sets very strong constraints on hypothesized particles from the dark sector, such as dark photons.

4. We have developed atom interferometry with "lukewarm" lithium atoms, opening up the possibility to do interferometry with a much wider class of atoms than available previously.

We will continue to develop atom interferometry for demonstrating the gravitational Aharonov-Bohm effect, and measuring fundamental constants very precisely. We will also work with the BECCAL science definition team and other teams to identify future targets for spaceborne fundamental physics. The interferometry work has several main thrusts. In the first thrust, we have been investigating how spaceborne atom interferometry can probe models for dark matter and dark energy. This has resulted in experimental demonstrations of such tests for so-called chameleon and symmetron models, and theoretical studies on how to make detailed predictions of the putative signals. In the second thrust, we have developed strategies to overcome systematic effects in atom interferometers that use Bragg diffraction, as the one planned for the Cold Atom lab. In the third, we have developed specific plans for spaceborne atom interferometry. We have collaborated with the German team Document for atom interferometry on the Cold Atom Lab and BECCAL. Plans include demonstrating long coherence times thanks to microgravity, tests of the equivalence principle, and searches for dark-energy candidates. They have also collaborated with Nan Yu (JPL) on a concept study QTEST (Quantum test of the Equivalence Principle and Spacer-Time) for testing the equivalence principle in space.

CLOCKS AND QUANTUM SENSORS & TECHNOLOGIES

We have demonstrated the first direct optical cooling to Bose-Einstein condensation, without any evaporative cooling. This has promising impact of simplifying spaceborne experiments. The Bose-Einstein condensation by direct optical cooling was achieved for small ensembles of ~1000 atom. We will attempt to make substantially larger condensates with the same method by using a more powerful trapping laser.

We have been working on spin squeezing in the optical-transition clock with trapped ytterbium atoms. By implementing both frequency and intensity feedback loops for the magical wavelength trap inside an optical cavity, we have now lengthened the trap lifetime for the Yb sample from 200 ms to 2 seconds. We have also started non-destructive state-dependent measurements for spin squeezing by observing the light transmitted through the cavity, and we can already more than resolve the shot-noise limit.

In the Rb experiment, we are working towards using Rydberg states for increasing the light-atom interaction in cavity QED. We have frequency-stabilized the control laser coupling the P state to high-lying Rydberg states.

We have demonstrated a new optical lattice clock configuration using a three-dimensional optical lattice, leading to measurement precision in the 19th decimal place. We have also demonstrated another record-breaking performance on stable lasers, with the narrowest laser linewidth at 10 mHz. We will Perform a clock comparison between this JILA Sr clock and the NIST Yb clock and Search for ultralight dark matter by comparing the Sr transition frequency with the resonance frequency of a crystalline cavity.

NEW DIRECTIONS

We have developed techniques for printing complex topological states on a spinor condensate that include the realization of skyrmions, spin-monopoles, alice states, and non-abelian spin textures that are particle-like excitations of the BEC matter wave field. We will investigate the realization of these and other phase/amplitude printing in space, where long interaction times will be possible.

The following paper is under review:

Azure Hansen, Justin T. Schultz, and Nicholas P. Bigelow "Generation of Monopole Spin Textures and Synthetic Fields in 87Rb Bose-Einstein Condensates" , in review (2017).

Task Progress As of December 2015:

ATOM INTERFEROMETRY

Demonstrate 50 pK kinetic temperatures and 30 photon recoil, 50% contrast, 1.1 s interrogation time atom interferometry (18 cm wavepacket separation).

First demonstration of a cavity-based atom interferometer. The cavity provides power enhancement, spatial filtering, and a precise beam geometry, enabling new techniques such as low power beamsplitters (<100 µW), large momentum transfer beamsplitters with modest power, or new self-aligned interferometer geometries. A manuscript has been accepted by Physical Review Letters and will be featured in an upcoming viewpoint article by Alex Cronin in Physics Today.

We have applied this novel technology to set limits on fifth forces that are undetectable in previous experiment by a "screening" mechanism which suppresses the forces in the vicinity of massive objects. Such theories have been studied in the context of dark matter and dark energy. Using atoms as test particles avoids triggering the screening and allows us to rule out a broad range of theories that could explain the observed cosmic acceleration. This work has been submitted for publication.

Clock Networks

Tested a novel quantum, cooperative protocol for operating a network of geographically remote optical atomic clocks.

Theoretically showed that such a network can be operated near the fundamental precision limit set by quantum theory. Furthermore, the internal structure of the network, combined with quantum communication techniques, guarantees security both from internal and external threats. Realization of such a global quantum network of clocks will allow construction of a real-time single international time scale (world clock) with unprecedented stability and accuracy.

We have initiated proof-of-concept experiments aimed at exploring key elements of such a network.

We have recently finished evaluation of our Sr II clock's total accuracy, and we have now reached 2.1 x 10^-18, an improvement of a factor of three over the previous world record.

We have started designing an optical cavity for collective measurement of Sr atoms in a cavity QED setting, in preparation for spin squeezing and connection between two clocks.

A goal is to demonstrate an entangled network of clocks.

We have taken two steps towards this goal:

(1) In our work towards an optical transition clock with Yb atoms that operates below the standard quantum limit, we have finished the assembly of an optical resonator operating in the strong coupling regime (peak cooperativity of 40), and are ready to install the system inside the vacuum chamber.

(2) We have achieve a magneto-optical trap for Yb both on the wide singlet transition, and on the narrow triplet transition that yields much lower atomic temperatures.

The remote entanglement between clocks will be achieved by communication via photonic quantum bits.

We have shown that a single photon can create a strongly entangled state of a large atomic ensemble containing 3000 Rb atoms.

We demonstrate that the atomic state upon detection of a single photon is characterized by a negative Wigner function, which represents the first observation of a negative Wigner function for a system containing more than a few atoms. Moreover, we also verify an entanglement depth (minimum number of mutually entangled atoms) comprising 90% of the ensemble.

We represent a research consortium of senior people, all pioneers in Bose-Einstein condensation, atom optics, atom interferometry, and related areas, with experience with NASA’s program on fundamental research in microgravity. The Consortium’s work is described in the context of four Tasks.

Task 1: Advanced Clocks in Space and Time Transfer

Task 2: Maturing and Advancing Atom Interferometer Technology for Space

Task 3: Precision Atom Interferometric Measurement in Space

Task 4: Strategies for the Frontier of Ultracold Atoms in Space.

The Consortium is: N. P. Bigelow, M. Kasevick, W. Ketterle, M. Lukin, H. Müller, W. D. Phillips, D. Pritchard, D. Stamper-Kurn, V. Vuletic, and J. Ye.

We have established a cooperation with German Scientists: C. Braxmaier, W. Ertmer, C. Lämmerzahl, A. Peters, E. M. Rasel, and W. P. Schleich. In forming this Consortium, we have several aims: (1) to, in one consolidated move, provide NASA with a community of talented and respected researchers who are committed to developing well thought out, highly impactful precision, quantum gas and atomic physics space experiments; (2) to support several first-class experimental efforts with significant potential to impact NASA interests and specifically to impact future flight experiments or indeed to become flight definition experiments; and (3) to provide intellectually compelling strategies that will impact future generations of flight experiments, aboard the International Space Station (ISS) and beyond. This consortium will provide NASA with a far larger return than could be expected from a series of individual projects. In part this is because of the natural synergies among the interests and expertise of the Consortium members. In part this is because the membership is meeting regularly in person and via teleconference in order to create and refine ideas beyond the work described at the formation of the consortium, challenging each other to advance only the most excellent projects to NASA.

The interests and expertise of the Consortium represent two of the four Thrusts identified in a recent National Research Council (NRC) report and the current NASA Research Announcement: (1) Precision Measurement of Fundamental Forces and Symmetries and (2) Quantum Gasses. In the present proposal we choose to focus on two specific areas: ultra-performance clocks and clock networks and atom interferometers (including those using degenerate quantum gasses). We have developed a cooperation plan with leading German expert scientists involved with DLR sponsored work in Bremen who are collaborators on this proposal.

Berkeley and Stanford lead Tasks 2 and 3.

MIT, U.C./JILA, and Harvard lead Task 1.

U. Md., Rochester, and MIT lead Task 4.

Members of the Consortium can and often will contribute to all four tasks with priorities being set by the lead institutions.

Atom interferometry:

Demonstrate 50 pK kinetic temperatures and 30 photon recoil, 50% contrast, 1.1 s interrogation time atom interferometry (18 cm wavepacket separation).

First demonstration of a cavity-based atom interferometer. The cavity provides power enhancement, spatial filtering, and a precise beam geometry, enabling new techniques such as low power beamsplitters (<100µW), large momentum transfer beamsplitters with modest power, or new self-aligned interferometer geometries. A manuscript has been accepted by Physical Review Letters and will be featured in an upcoming viewpoint article by Alex Cronin in Physics Today.

We have applied this novel technology to set limits on fifth forces that are undetectable in previous experiment by a "screening" mechanism which suppresses the forces in the vicinity of massive objects. Such theories have been studied in the context of dark matter and dark energy. Using atoms as test particles avoids triggering the screening and allows us to rule out a broad range of theories that could explain the observed cosmic acceleration. This work has been submitted for publication.

Clock Networks

Tested a novel quantum, cooperative protocol for operating a network of geographically remote optical atomic clocks.

Theoretically showed that such a network can be operated near the fundamental precision limit set by quantum theory. Furthermore, the internal structure of the network, combined with quantum communication techniques, guarantees security both from internal and external threats. Realization of such a global quantum network of clocks will allow construction of a real-time single international time scale (world clock) with unprecedented stability and accuracy.

We have initiated proof-of-concept experiments aimed at exploring key elements of such a network.

We have recently finished evaluation of our Sr II clock's total accuracy, and we have now reached 2.1 x 10^-18, an improvement of a factor of three over the previous world record.

We have started designing an optical cavity for collective measurement of Sr atoms in a cavity QED setting, in preparation for spin squeezing and connection between two clocks.

A goal is to demonstrate an entangled network of clocks.

We have taken two steps towards this goal.

(1) In our work towards an optical transition clock with Yb atoms that operates below the standard quantum limit, we have finished the assembly of an optical resonator operating in the strong coupling regime (peak cooperativity of 40), and are ready to install the system inside the vacuum chamber.

(2) We have achieve a magneto-optical trap for Yb both on the wide singlet transition, and on the narrow triplet transition that yields much lower atomic temperatures.

The remote entanglement between clocks will be achieved by communication via photonic quantum bits.

We have shown that a single photon can create a strongly entangled state of a large atomic ensemble containing 3000 Rb atoms.

We demonstrate that the atomic state upon detection of a single photon is characterized by a negative Wigner function, which represents the first observation of a negative Wigner function for a system containing more than a few atoms. Moreover, we also verify an entanglement depth (minimum number of mutually entangled atoms) comprising 90% of the ensemble.

Consortium for Ultracold Atoms in Space (CUAS)

The Consortium’s work is described in the context of four Tasks.

Task 1: Advanced Clocks in Space and Time Transfer

Task 2: Maturing and Advancing Atom Interferometer Technology for Space

Task 3: Precision Atom Interferometric Measurement in Space

Task 4: Strategies for the Frontier of Ultracold Atoms in Space.

The Consortium is: N. P. Bigelow, M. Kasevick, W. Ketterle, M. Lukin, H. Müller, W. D. Phillips, D. Pritchard, D. Stamper-Kurn, V. Vuletic, and J. Ye.

We have established a cooperation with German Scientists: C. Braxmaier, W. Ertmer, C. Lämmerzahl, A. Peters, E. M. Rasel, and W. P. Schleich.

We have made significant progress in the development of technologies for space based atom interferometer. Specifically, this includes preparation of some of the coldest atomic vapor samples ever realized on Earth (even colder samples will be created in Space in the future).

We have developed new and novel strategies for using atom interferometers in Space to set limits on dark matter and energy, addressing some of the most important open questions in Physics, questions that relate to the fundamental nature of space and time.

We are making significant progress on atomic clock technology and global synchronization. Terrestrial and Space based atomic clocks are vital to next generation GPS, navigation and ultra high speed, secure communication networks.

Several publications were in preparation as of January 1, 2015.

We request support for the formation and operation a research consortium of senior people, all pioneers in Bose-Einstein condensation, atom optics, atom interferometry, and related areas, with connections to NASA’s former program on fundamental research in microgravity. The Consortium’s work will be described in the context of four Tasks.

Task 1: Advanced Clocks in Space and Time Transfer

Task 2: Maturing and Advancing Atom Interferometer Technology for Space

Task 3: Precision Atom Interferometric Measurement in Space

Task 4: Strategies for the Frontier of Ultracold Atoms in Space.

The Consortium is: N. P. Bigelow, M. Kasevick, W. Ketterle, M. Lukin, H. Müller, W. D. Phillips, D. Pritchard, D. Stamper-Kurn, V. Vuletic and J. Ye.

We have established a cooperation with German Scientists: C. Braxmaier, W. Ertmer, C. Lämmerzahl, A. Peters, E. M. Rasel, and W. P. Schleich. In forming this Consortium, we have several aims: (1) to, in one consolidated move, provide NASA with a community of talented and respected researchers who are committed to developing well thought out, highly impactful precision, quantum gas and atomic physics space experiments; (2) to support several first-class experimental efforts with significant potential to impact NASA interests and specifically to impact future flight experiments or indeed to become flight definition experiments; and (3) to provide intellectually compelling strategies that will impact future generations of flight experiments, aboard ISS and beyond. We believe that by forming this consortium we will be able to provide NASA with a far larger return than could be expected from a series of individual projects. In part this is because of the natural synergies among the interests and expertise of the Consortium members. In part this is because the membership has explicitly agreed to meet regularly in person and via teleconference in order to create and refine ideas beyond the work described here, and to challenge each other to advance only the most excellent projects for support by NASA.

The interests and expertise of the Consortium represent two of the four Thrusts identified in a recent NRC report and the current NRA: (1) Precision Measurement of Fundamental Forces and Symmetries and (2) Quantum Gasses. In the present proposal we choose to focus on two specific areas: ultra-performance clocks and clock networks and atom interferometers (including those using degenerate quantum gasses). We have developed a cooperation plan with leading German expert scientists involved with DLR sponsored work in Bremen who are collaborators on this proposal.

Berkeley and Stanford will be leads on Tasks 2 and 3.

MIT, U.C./JILA and Harvard will be leads on Task 1.

U. Md., Rochester and MIT will be leads on Task 4.

Members of the Consortium can and often will contribute to all four tasks with priorities being set by the lead institutions.