Stanford University Departments of Physics & Applied Physics and the Ginzton Laboratory and QFARM Initiative
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? 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 associative memories---and quantum liquid crystals. As a first step toward the latter, we recently created a super solid that vibrates by forming an optical lattice with sound.
News
We have created the first spin glass made of atoms and photons! Read more
New theory paper in PRX explores the relationship between entanglement and replica symmetry…
What first got you excited about science?Mostly science fiction, to be honest! I was a big star…
We report in PRX Quantum the extremely large cooperativity of our active quantum gas microscope.
Our paper has appeared in Nature regarding the creation of the first optical lattice with sound…
New theoretical work appeared in PRX and was highlighted in an APS Physics Synopsis. It marks a…
Read news article "Quantum Simulation Stars Light in the Role of Sound" by Bailey Bedford on our…
New theory paper in PRL shows how to use photon-mediated interactions in a multimode optical cavity…
We demonstrated dynamical spin-orbit-coupling in a BEC for the first time using an optical cavity…
Two papers, here and here, show how Gouy phases modify photon-mediated interactions in multimode…
PRX paper published. Results demostrate tunable range, photon-mediated atom-atom interactions…
APS Physics Viewpoint on our paper reporting tunable atom-atom interactions in multimode cavity QED…
A new nonequilibrium state of matter. To appear in Phys Rev Applied. ArXiv version
Digital Micromirror Devices (DMD) provide a robust platform with which to implement digital…
We present a novel cavity QED system in which a Bose-Einstein condensate (BEC) is trapped within a…
Paper on neural network in multimode cavity. Special issue in honor David Sherrington.
Theory paper on soft quantum matter in multimode cavity QED published in Phys. Rev. A and selected…
A method to observe supersolids and superstripes? Lev helps propose a multimode cavity QED…
Spin glass and Hopefield neural network in multimode cQED paper appears in PRL. Collaboration…
Team Members
Publications
B. P. Marsh, R. M. Kroeze, S. Ganguli, S. Gopalakrishnan, J. Keeling, and B. L. Lev
Entanglement and replica symmetry breaking in a driven-dissipative quantum spin glass
Physical Review X 14, 011026 (2024). pdf
arXiv:2307.10176
R. M. Kroeze, B. P. Marsh, D. Atri Schuller, H. Hunt, S. Gopalakrishnan, J. Keeling, and B. L. Lev
Replica symmetry breaking in a quantum-optical vector spin glass
arXiv:2311.04216 pdf
R. M. Kroeze, B. P. Marsh, K.-Y. Lin, J. Keeling, and B. L. Lev
High Cooperativity Using a Confocal-Cavity–QED Microscope
PRX Quantum 4, 020326 (2023). pdf
arXiv:2212.06716
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
arXiv:2104.13922
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
arxiv:2002.12285
R. M. Kroeze, Y. Guo, and B. L. Lev
Dynamical spin-orbit coupling of a quantum gas
Physical Review Letters 123, 160404 (2019). pdf
arXiv:1904.08388
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
arXiv:1810.11086
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
arXiv:1708.08933
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
arXiv:1606.04127
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
arXiv:1608.07246
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
arXiv:1603.06900
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
arXiv:1411.5443
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