Many-Body Cavity QED

Many-Body Cavity QED

What is a quantum neural network and how might it exhibit computational advantage? Can we create a spin glass made of atomic spins and photons and use it to resolve longstanding mysteries surrounding spin-glass order? Could BEC matter waves interacting via photons mimic the quantum liquid crystals found in high-Tc superconductors? If so, what might we learn? We are tackling these fundamental and technologically relevant questions using our novel multimode cavity QED-BEC apparatus. The system provides strong, photon-mediated interactions among atoms trapped within the cavity resonator.  Photons virtually scattered among the atoms cause the system to superradiate and self-organize into various exotic forms of quantum matter such as quantum spin glasses---which can be used as quantum neural networks---and quantum liquid crystals. We have recently demonstrated the necessary ingredients needed to realize these exotic systems. Moreover, we are investigating whether quantum neural networks based on these driven-dissipative quantum systems may provide for finding solutions to NP-hard optimization problems.


LevLab An optical lattice with sound

Our paper has appeared in Nature regarding the creation of the first optical lattice with sound vibrations---... Read More

Lev lab cavity

Read news article "Quantum Simulation Stars Light in the Role of... Read More

New theory paper in PRL shows how to use photon-mediated... Read More

dynamical SOC

We demonstrated dynamical spin-orbit-coupling in a BEC for the first time... Read More

spinor polariton condensate from LevLab

We made a spinor polariton condensate.  Published in PRL. Read more... Read More

Tunable cavity interactions PRX

PRX paper published.  Results demostrate tunable range, photon-... Read More

Proposal for creating Meissner-like effect in multimode cavity QED.

Turtle mode

A new nonequilibrium state of matter.  To appear in Phys Rev Applied.  ArXiv version 

Dr. Alicia Kollar

Congratulations Alicia Kollár, PhD!

Dr. Alexander Pagageorge

Congratuations to Alexander Pagageorge, PhD!


Digital Micromirror Devices (DMD) provide a robust platform with which to implement digital holography, in principle providing the means to... Read More


We present a novel cavity QED system in which a Bose-Einstein condensate (... Read More

Paper on neural network in multimode cavity.  Special... Read More

Spin glass and Hopefield neural network in multimode cQED paper appears in PRL.  ... Read More

Theory paper on soft quantum matter in multimode cavity QED published in Phys. Rev. A... Read More


Y. Guo, R. M. Kroeze, B. P. Marsh, S. Gopalakrishnan, J. Keeling, and B. L. Lev
An optical lattice with sound
Nature 599, 211 (2021).  link to pdf
News coverage:
Stanford News:  Adding sound to quantum simulations
APS Physics Magazine:  A Humming Lattice of Cold Atoms

B. P. Marsh, Y. Guo, R. M. Kroeze, S. Gopalakrishnan, S. Ganguli, J. Keeling, and B. L. Lev
Enhancing associative memory recall and storage capacity using confocal cavity QED
Physical Review X 11, 021048 (2021).  pdf
News coverage:
APS Synopsis in Physics:  A Computer Memory Based on Cold Atoms and Light
APS DAMOP Highlight: Atoms and Light Remember Better
arXiv:2009.01227  pdf

C. Rylands, Y. Guo, B. L. Lev, J. Keeling, and V. Galitski
Photon-mediated Peierls Transition of a 1D Gas in a Multimode Optical Cavity
Physical Review Letters 125, 010404 (2020).  pdf
News coverage:
 "Quantum Simulation Stars Light in the Role of Sound" by Bailey Bedford

R. M. Kroeze, Y. Guo, and B. L. Lev
Dynamical spin-orbit coupling of a quantum gas
Physical Review Letters 123, 160404 (2019). pdf

Y. Guo, V. D. Vaidya, R. M. Kroeze, R. A. Lunney, B. L. Lev, and J. Keeling
Emergent and broken symmetries of atomic self-organization arising from Gouy phase shifts in multimode cavity QED
Physical Review A 99, 053818 (2019).  pdf
Selected for Editors' Suggestion
Featured in Physics Synopsis: A Step Toward Simulating Spin Glasses.  pdf
arXiv:1810.11085  pdf
Erratum: Physical Review A 103, 019901(E) (2021).  pdf

Y. Guo, R. M. Kroeze, V. D. Vaidya, J. Keeling, and B. L. Lev
Sign-changing photon-mediated atom interactions in multimode cavity QED
Physical Review Letters 122, 193601 (2019).  pdf
Selected for Editors' Suggestion
Featured in Physics Synopsis: A Step Toward Simulating Spin Glasses.  pdf

R. M. Kroeze, Y. Guo, V. D. Vaidya, J. Keeling, and B. L. Lev
Spinor self-ordering of a quantum gas in a cavity
Physical Review Letters 121, 163601 (2018). 
arXiv:1807.04915  pdf 

V. D. Vaidya, Y. Guo, R. M. Kroeze, K. E. Ballantine, A. J. Kollár, J. Keeling, and B. L. Lev
Tunable-range, photon-mediated atomic interactions in multimode cavity QED​
Physical Review X 8, 011002 (2018).  pdf
Selected for a Viewpoint in APS Physics:
H. Türeci, 
A Multimode Dial for Interatomic Interactions, pdf

A. J. Kollár, A. T. Papageorge, V. D. Vaidya, Y. Guo, J. Keeling, and B. L. Lev
Supermode-density-wave-polariton condensation
Nature Communications 8, 14386 (2017). pdf

K. E. Ballantine, B. L. Lev, and J. Keeling
Meissner-like effect for synthetic gauge field in multimode cavity QED​
Physical Review Letters 118, 045302 (2017).  pdf

A. T. Papageorge, A. J. Kollár, and B. L. Lev
Coupling to Modes of a Near-Confocal Optical Resonator Using a Digital Light Modulator
Optics Express 24, 11447 (2016). pdf

A. Kollár, A. Papageorge, K. Baumann, M. Armen, and B. L. Lev
An adjustable-length cavity and Bose-Einstein condensate apparatus for multimode cavity QED 
New Journal of Physics 17, 043012 (2015). pdf

S. Gopalakrishnan, B. L. Lev, and P. Goldbart
Frustration and glassiness in spin models with cavity-mediated interactions
Physical Review Letters 107, 277201 (2011). pdf

S. Gopalakrishnan, B. L. Lev, and P. Goldbart
Exploring models of associative memory via cavity quantum electrodynamics
Philosophical Magazine, 92, 353 (2012).
Special issue in honor of David Sherrington

S. Gopalakrishnan, B. L. Lev, and P. Goldbart
Atom-light crystallization of BECs in multimode cavities: Nonequilibrium classical and quantum phase transitions, emergent lattices, supersolidity, and frustration
Physical Review A 82, 043612 (2010). pdf
Selected for a Viewpoint in APS Physics

S. Gopalakrishnan, B. L. Lev, and P. Goldbart
Emergent crystallinity and frustration with Bose-Einstein condensates in multimode cavities
Nature Physics 5, 845 - 850 (2009).
Nature Physics News and Views article by Helmut Ritsch.
arXiv:cond-mat/0903.2254 pdf

Homepage Project Description: 

Quantum neural networks, quantum spin glasses, and quantum liquid crystals are studied using photon-mediated interactions provided by our novel multimode cavity QED-BEC system.

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