Benjamin Lev is a Professor of Physics and Applied Physics professor at Stanford University. He received his Bachelor’s degree Magna Cum Laude from Princeton in 1999 and his Ph.D. from Caltech in 2005, both in Physics. Benjamin was a National Research Council postdoc at JILA and an Assistant Professor at the University of Illinois at Urbana-Champaign. He joined the Stanford faculty in 2011, where he is an Associate Professor in the Departments of Physics and Applied Physics. Benjamin has received a Packard Foundation Fellowship and the Presidential Early Career Award for Scientists and Engineers (PECASE) award from President Obama. In addition, he received the NSF CAREER award and the Air Force Office of Scientific Research, DARPA, and Office of Naval Research Young Investigator Program awards. Benjamin’s research focuses on exploring quantum many-body physics, including quantum neural networks, using techniques at the interface of ultracold atomic physics, quantum optics, and condensed matter physics. He is an APS Fellow and a member of the Defense Science Study Group. His research has been funded by the NSF, DOE, ARO, AFOSR, ONR, DARPA, NTT, and the Moore Foundation.

Benjamin’s research focuses on exploring quantum many-body physics, including quantum neural networks, using techniques at the interface of ultracold atomic physics, quantum optics, and condensed matter physics.

Academic Appointments

Honors & Awards

  • Fellow of the American Physical Society, APS (2021)
  • Editorial Board, Physical Review X, American Physical Society (2021)
  • Defense Science Study Group, IDA & DARPA (2020)
  • Chambers Fellowship, Stanford University (2015)
  • Terman Fellowship, Stanford University (2014)
  • Young Faculty Award (YFA), DARPA (2012)
  • Young Investigator Award (ONR YIP), Office of Naval Research (2012)
  • Presidential Early Career Award for Scientists and Engineers (PECASE), NSF (2011)
  • Terman Fellowship, Stanford University (2011)
  • Packard Fellowship, David and Lucile Packard Foundation (2010)
  • NSF CAREER Award, National Science Foundation (NSF) (2008)
  • Office of Scientific Research Young Investigator Award (AFOSR YIP), Air Force (2008)
  • Everhart Distinguished Graduate Student Lectureship, Caltech (2004)
  • Allen Goodrich Schenstone Prize for Outstanding Work in Experimental Physics, Department of Physics, Princeton University (1999)

Professional Education

  • Ph.D., California Institute of Technology, Physics (2005)
  • A.B., Princeton University, Physics, Magna Cum Laude (1999)
  • Valedictorian, Crystal River High School (1995)

Current Research and Scholarly Interests

LevLab is a joint AMO & CM experimental group that explores the question: Can new classes of states and phases of quantum matter be created far away from equilibrium, and if so, what do we learn? We use our new technique, confocal cavity QED, to both engineer out-of-equilibrium quantum gases and 2D materials and to image and control their new properties.

Specifically, we aim to:

-Create and control new forms of highly excited quantum matter using cavity photons coupled to 1D gases of the most magnetic atom, dysprosium;

-`Wire together' nodes of atomic spins with photons to create novel spin glasses and the quantum neural networks they realize;

-Use our novel `CavMat' instrument to control electronic excitations of twisted 2D quantum materials with the goal to shape control their phase diagrams.

We welcome all curious experiment and theory grad students and postdocs to contact Prof. Lev.

2023-24 Courses

Stanford Advisees

All Publications

  • Entanglement and Replica Symmetry Breaking in a Driven-Dissipative Quantum Spin Glass PHYSICAL REVIEW X Marsh, B. P., Kroeze, R. M., Ganguli, S., Gopalakrishnan, S., Keeling, J., Lev, B. L. 2024; 14 (1)
  • Rapidity and momentum distributions of one-dimensional dipolar quantum gases PHYSICAL REVIEW A Li, K., Zhang, Y., Yang, K., Lin, K., Gopalakrishnan, S., Rigol, M., Lev, B. L. 2023; 107 (6)
  • High Cooperativity Using a Confocal-Cavity-QED Microscope PRX QUANTUM Kroeze, R. M., Marsh, B. P., Lin, K., Keeling, J., Lev, B. L. 2023; 4 (2)
  • Dipolar physics: a review of experiments with magnetic quantum gases. Reports on progress in physics. Physical Society (Great Britain) Chomaz, L., Ferrier-Barbut, I., Ferlaino, F., Laburthe-Tolra, B., Lev, B. L., Pfau, T. 2022; 86 (2)


    Since the achievement of quantum degeneracy in gases of chromium atoms in 2004, the experimental investigation of ultracold gases made of highly magnetic atoms has blossomed. The field has yielded the observation of many unprecedented phenomena, in particular those in which long-range and anisotropic dipole-dipole interactions (DDIs) play a crucial role. In this review, we aim to present the aspects of the magnetic quantum-gas platform that make it unique for exploring ultracold and quantum physics as well as to give a thorough overview of experimental achievements. Highly magnetic atoms distinguish themselves by the fact that their electronic ground-state configuration possesses a large electronic total angular momentum. This results in a large magnetic moment and a rich electronic transition spectrum. Such transitions are useful for cooling, trapping, and manipulating these atoms. The complex atomic structure and large dipolar moments of these atoms also lead to a dense spectrum of resonances in their two-body scattering behaviour. These resonances can be used to control the interatomic interactions and, in particular, the relative importance of contact over dipolar interactions. These features provide exquisite control knobs for exploring the few- and many-body physics of dipolar quantum gases. The study of dipolar effects in magnetic quantum gases has covered various few-body phenomena that are based on elastic and inelastic anisotropic scattering. Various many-body effects have also been demonstrated. These affect both the shape, stability, dynamics, and excitations of fully polarised repulsive Bose or Fermi gases. Beyond the mean-field instability, strong dipolar interactions competing with slightly weaker contact interactions between magnetic bosons yield new quantum-stabilised states, among which are self-bound droplets, droplet assemblies, and supersolids. Dipolar interactions also deeply affect the physics of atomic gases with an internal degree of freedom as these interactions intrinsically couple spin and atomic motion. Finally, long-range dipolar interactions can stabilise strongly correlated excited states of 1D gases and also impact the physics of lattice-confined systems, both at the spin-polarised level (Hubbard models with off-site interactions) and at the spinful level (XYZ models). In the present manuscript, we aim to provide an extensive overview of the various related experimental achievements up to the present.

    View details for DOI 10.1088/1361-6633/aca814

    View details for PubMedID 36583342

  • An optical lattice with sound. Nature Guo, Y., Kroeze, R. M., Marsh, B. P., Gopalakrishnan, S., Keeling, J., Lev, B. L. 2021; 599 (7884): 211-215


    Quantized sound waves-phonons-govern the elastic response of crystalline materials, and also play an integral part in determining their thermodynamic properties and electrical response (for example, by binding electrons into superconducting Cooper pairs)1-3. The physics of lattice phonons and elasticity is absent in simulators of quantum solids constructed of neutral atoms in periodic light potentials: unlike real solids, traditional optical lattices are silent because they are infinitely stiff4. Optical-lattice realizations of crystals therefore lack some of the central dynamical degrees of freedom that determine the low-temperature properties of real materials. Here, we create an optical lattice with phonon modes using a Bose-Einstein condensate (BEC) coupled to a confocal optical resonator. Playing the role of an active quantum gas microscope, the multimode cavity QED system both images the phonons and induces the crystallization that supports phonons via short-range, photon-mediated atom-atom interactions. Dynamical susceptibility measurements reveal the phonon dispersion relation, showing that these collective excitations exhibit a sound speed dependent on the BEC-photon coupling strength. Our results pave the way for exploring the rich physics of elasticity in quantum solids, ranging from quantum melting transitions5 to exotic 'fractonic' topological defects6 in the quantum regime.

    View details for DOI 10.1038/s41586-021-03945-x

    View details for PubMedID 34759361

  • Enhancing Associative Memory Recall and Storage Capacity Using Confocal Cavity QED PHYSICAL REVIEW X Marsh, B. P., Guo, Y., Kroeze, R. M., Gopalakrishnan, S., Ganguli, S., Keeling, J., Lev, B. L. 2021; 11 (2)
  • A scanning quantum cryogenic atom microscope at 6 K SCIPOST PHYSICS Taylor, S. F., Yang, F., Freudenstein, B. A., Lev, B. L. 2021; 10 (3)
  • Quantum Simulators: Architectures and Opportunities PRX QUANTUM Altman, E., Brown, K. R., Carleo, G., Carr, L. D., Demler, E., Chin, C., DeMarco, B., Economou, S. E., Eriksson, M. A., Fu, K. C., Greiner, M., Hazzard, K. A., Hulet, R. G., Kollar, A. J., Lev, B. L., Lukin, M. D., Ma, R., Mi, X., Misra, S., Monroe, C., Murch, K., Nazario, Z., Ni, K., Potter, A. C., Roushan, P., Saffman, M., Schleier-Smith, M., Siddiqi, I., Simmonds, R., Singh, M., Spielman, I. B., Temme, K., Weiss, D. S., Vuckovic, J., Vuletic, V., Ye, J., Zwierlein, M. 2021; 2 (1)
  • Topological pumping of a 1D dipolar gas into strongly correlated prethermal states. Science (New York, N.Y.) Kao, W. n., Li, K. Y., Lin, K. Y., Gopalakrishnan, S. n., Lev, B. L. 2021; 371 (6526): 296–300


    Long-lived excited states of interacting quantum systems that retain quantum correlations and evade thermalization are of great fundamental interest. We create nonthermal states in a bosonic one-dimensional (1D) quantum gas of dysprosium by stabilizing a super-Tonks-Girardeau gas against collapse and thermalization with repulsive long-range dipolar interactions. Stiffness and energy-per-particle measurements show that the system is dynamically stable regardless of contact interaction strength. This enables us to cycle contact interactions from weakly to strongly repulsive, then strongly attractive, and finally weakly attractive. We show that this cycle is an energy-space topological pump (caused by a quantum holonomy). Iterating this cycle offers an unexplored topological pumping method to create a hierarchy of increasingly excited prethermal states.

    View details for DOI 10.1126/science.abb4928

    View details for PubMedID 33446558

  • Photon-Mediated Peierls Transition of a 1D Gas in a Multimode Optical Cavity. Physical review letters Rylands, C., Guo, Y., Lev, B. L., Keeling, J., Galitski, V. 2020; 125 (1): 010404


    The Peierls instability toward a charge density wave is a canonical example of phonon-driven strongly correlated physics and is intimately related to topological quantum matter and exotic superconductivity. We propose a method for realizing an analogous photon-mediated Peierls transition, using a system of one-dimensional tubes of interacting Bose or Fermi atoms trapped inside a multimode confocal cavity. Pumping the cavity transversely engineers a cavity-mediated metal-to-insulator transition in the atomic system. For strongly interacting bosons in the Tonks-Girardeau limit, this transition can be understood (through fermionization) as being the Peierls instability. We extend the calculation to finite values of the interaction strength and derive analytic expressions for both the cavity field and mass gap. They display nontrivial power law dependence on the dimensionless matter-light coupling.

    View details for DOI 10.1103/PhysRevLett.125.010404

    View details for PubMedID 32678647

  • Photon-Mediated Peierls Transition of a 1D Gas in a Multimode Optical Cavity PHYSICAL REVIEW LETTERS Rylands, C., Guo, Y., Lev, B. L., Keeling, J., Galitski, V. 2020; 125 (1)
  • Nematic transitions in iron pnictide superconductors imaged with a quantum gas NATURE PHYSICS Yang, F., Taylor, S. F., Edkins, S. D., Palmstrom, J. C., Fisher, I. R., Lev, B. L. 2020
  • Dynamical Spin-Orbit Coupling of a Quantum Gas PHYSICAL REVIEW LETTERS Kroeze, R. M., Guo, Y., Lev, B. L. 2019; 123 (16)
  • Sign-Changing Photon-Mediated Atom Interactions in Multimode Cavity Quantum Electrodynamics PHYSICAL REVIEW LETTERS Guo, Y., Kroeze, R. M., Vaidya, V. D., Keeling, J., Lev, B. L. 2019; 122 (19): 193601


    Sign-changing interactions constitute a crucial ingredient in the creation of frustrated many-body systems such as spin glasses. We present here the demonstration of a photon-mediated sign-changing interaction between Bose-Einstein-condensed atoms in a confocal cavity. The interaction between two atoms is of an unusual, nonlocal form proportional to the cosine of the inner product of the atoms' position vectors. This interaction arises from the differing Gouy phase shifts of the cavity's degenerate modes. The interaction drives a nonequilibrium Dicke-type phase transition in the system leading to atomic checkerboard density-wave order. Because of the Gouy phase anomalies, the checkerboard pattern can assume either a sinelike or cosinelike character. This state is detected via the holographic imaging of the cavity's superradiant emission. Together with a companion paper [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 phases in multimode cavity QED, Phys. Rev. A 99, 053818 (2019)PLRAAN2469-992610.1103/PhysRevA.99.053818], we explore this interaction's influence on superradiant phase transitions in multimode cavities. Employing this interaction in cavity QED spin systems may enable the creation of artificial spin glasses and quantum neural networks.

    View details for DOI 10.1103/PhysRevLett.122.193601

    View details for Web of Science ID 000468228200005

    View details for PubMedID 31144918

  • Emergent and broken symmetries of atomic self-organization arising from Gouy phase shifts in multimode cavity QED PHYSICAL REVIEW A Guo, Y., Vaidya, V. D., Kroeze, R. M., Lunney, R. A., Lev, B. L., Keeling, J. 2019; 99 (5)
  • Spinor Self-Ordering of a Quantum Gas in a Cavity. Physical review letters Kroeze, R. M., Guo, Y., Vaidya, V. D., Keeling, J., Lev, B. L. 2018; 121 (16): 163601


    We observe the joint spin-spatial (spinor) self-organization of a two-component Bose-Einstein condensate (BEC) strongly coupled to an optical cavity. This unusual nonequilibrium Hepp-Lieb-Dicke phase transition is driven by an off-resonant Raman transition formed from a classical pump field and the emergent quantum dynamical cavity field. This mediates a spinor-spinor interaction that, above a critical strength, simultaneously organizes opposite spinor states of the BEC on opposite checkerboard configurations of an emergent 2D lattice. The resulting spinor density-wave polariton condensate is observed by directly detecting the atomic spin and momentum state and by holographically reconstructing the phase of the emitted cavity field. The latter provides a direct measure of the spin state, and a spin-spatial domain wall is observed. The photon-mediated spin interactions demonstrated here may be engineered to create dynamical gauge fields and quantum spin glasses.

    View details for DOI 10.1103/PhysRevLett.121.163601

    View details for PubMedID 30387632

  • Spinor Self-Ordering of a Quantum Gas in a Cavity PHYSICAL REVIEW LETTERS Kroeze, R. M., Guo, Y., Vaidya, V. D., Keeling, J., Lev, B. L. 2018; 121 (16)
  • Tuning the Dipole-Dipole Interaction in a Quantum Gas with a Rotating Magnetic Field PHYSICAL REVIEW LETTERS Tang, Y., Kao, W., Li, K., Lev, B. L. 2018; 120 (23): 230401


    We demonstrate the tuning of the magnetic dipole-dipole interaction (DDI) within a dysprosium Bose-Einstein condensate by rapidly rotating the orientation of the atomic dipoles. The tunability of the dipolar mean-field energy manifests as a modified gas aspect ratio after time-of-flight expansion. We demonstrate that both the magnitude and the sign of the DDI can be tuned using this technique. In particular, we show that a magic rotation angle exists at which the mean-field DDI can be eliminated, and at this angle, we observe that the expansion dynamics of the condensate is close to that predicted for a nondipolar gas. The ability to tune the strength of the DDI opens new avenues toward the creation of exotic soliton and vortex states as well as unusual quantum lattice phases and Weyl superfluids.

    View details for PubMedID 29932688

  • Thermalization near Integrability in a Dipolar Quantum Newton's Cradle PHYSICAL REVIEW X Tang, Y., Kao, W., Li, K., Seo, S., Mallayya, K., Rigol, M., Gopalakrishnan, S., Lev, B. L. 2018; 8 (2)
  • Tunable-Range, Photon-Mediated Atomic Interactions in Multimode Cavity QED PHYSICAL REVIEW X Vaidya, V. D., Guo, Y., Kroeze, R. M., Ballantine, K. E., Kollar, A. J., Keeling, J., Lev, B. L. 2018; 8 (1)
  • Scanning Quantum Cryogenic Atom Microscope PHYSICAL REVIEW APPLIED Yang, F., Kollar, A. J., Taylor, S. F., Turner, R. W., Lev, B. L. 2017; 7 (3)
  • Anisotropic dependence of tune-out wavelength near Dy 741-nm transition OPTICS EXPRESS Kao, W., Tang, Y., Burdick, N. Q., Lev, B. L. 2017; 25 (4): 3411-3419


    We report the first measurement of a tune-out wavelength for ground-state bosonic Dy and linearly polarized light. The tune-out wavelength is measured as a detuning from the nearby narrow-line 741-nm transition in 162Dy, and is the wavelength at which the total Stark shift of the ground state vanishes. We find that it strongly depends on the relative angle between the optical field and quantization axis due to Dy's large tensor polarizability. This anisotropy provides a wide, 22-GHz tunability of the tune-out frequency for linearly polarized light, in contrast to Rb and Cs whose near-infrared tune-out wavelengths do not exhibit large anisotropy. The measurements of the total light shift are performed by measuring the contrast of multipulse Kapitza-Dirac diffraction. The calculated wavelengths are within a few GHz of the measured values using known Dy electronic transition data. The lack of hyperfine structure in bosonic Dy implies that the tune-out wavelengths for the other bosonic Dy isotopes should be related to this 162Dy measurement by the known isotope shifts.

    View details for DOI 10.1364/OE.25.003411

    View details for Web of Science ID 000397317400051

    View details for PubMedID 28241555

  • Supermode-density-wave-polariton condensation with a Bose-Einstein condensate in a multimode cavity. Nature communications Kollár, A. J., Papageorge, A. T., Vaidya, V. D., Guo, Y., Keeling, J., Lev, B. L. 2017; 8: 14386-?


    Phase transitions, where observable properties of a many-body system change discontinuously, can occur in both open and closed systems. By placing cold atoms in optical cavities and inducing strong coupling between light and excitations of the atoms, one can experimentally study phase transitions of open quantum systems. Here we observe and study a non-equilibrium phase transition, the condensation of supermode-density-wave polaritons. These polaritons are formed from a superposition of cavity photon eigenmodes (a supermode), coupled to atomic density waves of a quantum gas. As the cavity supports multiple photon spatial modes and because the light-matter coupling can be comparable to the energy splitting of these modes, the composition of the supermode polariton is changed by the light-matter coupling on condensation. By demonstrating the ability to observe and understand density-wave-polariton condensation in the few-mode-degenerate cavity regime, our results show the potential to study similar questions in fully multimode cavities.

    View details for DOI 10.1038/ncomms14386

    View details for PubMedID 28211455

    View details for PubMedCentralID PMC5321730

  • Meissner-like Effect for a Synthetic Gauge Field in Multimode Cavity QED PHYSICAL REVIEW LETTERS Ballantine, K. E., Lev, B. L., Keeling, J. 2017; 118 (4)


    Previous realizations of synthetic gauge fields for ultracold atoms do not allow the spatial profile of the field to evolve freely. We propose a scheme which overcomes this restriction by using the light in a multimode cavity with many nearly degenerate transverse modes, in conjunction with Raman coupling, to realize an artificial magnetic field which acts on a Bose-Einstein condensate of neutral atoms. We describe the evolution of such a system and present the results of numerical simulations which show dynamical coupling between the effective field and the matter on which it acts. Crucially, the freedom of the spatial profile of the field is sufficient to realize a close analogue of the Meissner effect, where the magnetic field is expelled from the superfluid. This backaction of the atoms on the synthetic field distinguishes the Meissner-like effect described here from the Hess-Fairbank suppression of rotation in a neutral superfluid observed elsewhere.

    View details for DOI 10.1103/PhysRevLett.118.045302

    View details for Web of Science ID 000394335800017

    View details for PubMedID 28186789

  • Anisotropic collisions of dipolar Bose-Einstein condensates in the universal regime NEW JOURNAL OF PHYSICS Burdick, N. Q., Sykes, A. G., Tang, Y., Lev, B. L. 2016; 18
  • Anisotropic Expansion of a Thermal Dipolar Bose Gas PHYSICAL REVIEW LETTERS Tang, Y., SYKES, A. G., Burdick, N. Q., DiSciacca, J. M., Petrov, D. S., Lev, B. L. 2016; 117 (15)


    We report on the anisotropic expansion of ultracold bosonic dysprosium gases at temperatures above quantum degeneracy and develop a quantitative theory to describe this behavior. The theory expresses the postexpansion aspect ratio in terms of temperature and microscopic collisional properties by incorporating Hartree-Fock mean-field interactions, hydrodynamic effects, and Bose-enhancement factors. Our results extend the utility of expansion imaging by providing accurate thermometry for dipolar thermal Bose gases. Furthermore, we present a simple method to determine scattering lengths in dipolar gases, including near a Feshbach resonance, through observation of thermal gas expansion.

    View details for DOI 10.1103/PhysRevLett.117.155301

    View details for Web of Science ID 000384612000003

    View details for PubMedID 27768342

  • Long-Lived Spin-Orbit-Coupled Degenerate Dipolar Fermi Gas PHYSICAL REVIEW X Burdick, N. Q., Tang, Y., Lev, B. L. 2016; 6 (3)
  • Coupling to modes of a near-confocal optical resonator using a digital light modulator OPTICS EXPRESS Papageorge, A. T., Kollar, A. J., Lev, B. L. 2016; 24 (11): 1447-1457
  • Bilayer fractional quantum Hall states with dipoles PHYSICAL REVIEW A YAO, N. Y., Bennett, S. D., Laumann, C. R., Lev, B. L., Gorshkov, A. V. 2015; 92 (3)
  • s-wave scattering lengths of the strongly dipolar bosons Dy-162 and Dy-164 PHYSICAL REVIEW A Tang, Y., Sykes, A., Burdick, N. Q., Bohn, J. L., Lev, B. L. 2015; 92 (2)
  • Bose-Einstein condensation of Dy-162 and Dy-160 NEW JOURNAL OF PHYSICS Tang, Y., Burdick, N. Q., Baumann, K., Lev, B. L. 2015; 17
  • An adjustable-length cavity and Bose-Einstein condensate apparatus for multimode cavity QED NEW JOURNAL OF PHYSICS Kollar, A. J., Papageorge, A. T., Baumann, K., Armen, M. A., Lev, B. L. 2015; 17
  • Fermionic suppression of dipolar relaxation. Physical review letters Burdick, N. Q., Baumann, K., Tang, Y., Lu, M., Lev, B. L. 2015; 114 (2): 023201-?


    We observe the suppression of inelastic dipolar scattering in ultracold Fermi gases of the highly magnetic atom dysprosium: the more energy that is released, the less frequently these exothermic reactions take place, and only quantum spin statistics can explain this counterintuitive effect. Inelastic dipolar scattering in nonzero magnetic fields leads to heating or to loss of the trapped population, both detrimental to experiments intended to study quantum many-body physics with strongly dipolar gases. Fermi statistics, however, is predicted to lead to a kinematic suppression of these harmful reactions. Indeed, we observe a 120-fold suppression of dipolar relaxation in fermionic versus bosonic Dy, as expected from theory describing universal inelastic dipolar scattering, though never before experimentally confirmed. Similarly, low inelastic cross sections are observed in spin mixtures, also with striking correspondence to predictions. The suppression of relaxation opens the possibility of employing fermionic dipolar species in studies of quantum many-body physics involving, e.g., synthetic gauge fields and pairing.

    View details for PubMedID 25635544

  • Fermionic Suppression of Dipolar Relaxation PHYSICAL REVIEW LETTERS Burdick, N. Q., Baumann, K., Tang, Y., Lu, M., Lev, B. L. 2015; 114 (2)
  • Observation of low-field Fano-Feshbach resonances in ultracold gases of dysprosium PHYSICAL REVIEW A Baumann, K., Burdick, N. Q., Lu, M., Lev, B. L. 2014; 89 (2)
  • Trapping ultracold gases near cryogenic materials with rapid reconfigurability APPLIED PHYSICS LETTERS Naides, M. A., Turner, R. W., Lai, R. A., DiSciacca, J. M., Lev, B. L. 2013; 103 (25)

    View details for DOI 10.1063/1.4852017

    View details for Web of Science ID 000329973800012

  • Synthetic gauge field with highly magnetic lanthanide atoms PHYSICAL REVIEW A Cui, X., Lian, B., Ho, T., Lev, B. L., Zhai, H. 2013; 88 (1)
  • Imaging topologically protected transport with quantum degenerate gases PHYSICAL REVIEW B Dellabetta, B., Hughes, T. L., Gilbert, M. J., Lev, B. L. 2012; 85 (20)
  • Quantum Degenerate Dipolar Fermi Gas PHYSICAL REVIEW LETTERS Lu, M., Burdick, N. Q., Lev, B. L. 2012; 108 (21)


    We report the first quantum degenerate dipolar Fermi gas, the realization of which opens a new frontier for exploring strongly correlated physics and, in particular, quantum liquid crystalline phases. A quantum degenerate Fermi gas of the most magnetic atom 161Dy is produced by laser cooling to 10 μK before sympathetically cooling with ultracold, bosonic 162Dy. The temperature of the spin-polarized 161Dy is a factor T/T(F)=0.2 below the Fermi temperature T(F)=300 nK. The cotrapped 162Dy concomitantly cools to approximately T(c) for Bose-Einstein condensation, thus realizing a novel, nearly quantum degenerate dipolar Bose-Fermi gas mixture. Additionally, we achieve the forced evaporative cooling of spin-polarized 161Dy without 162Dy to T/T(F)=0.7. That such a low temperature ratio is achieved may be a first signature of universal dipolar scattering.

    View details for DOI 10.1103/PhysRevLett.108.215301

    View details for Web of Science ID 000304250000015

    View details for PubMedID 23003275

  • Atomic interface between microwave and optical photons PHYSICAL REVIEW A Hafezi, M., Kim, Z., Rolston, S. L., OROZCO, L. A., Lev, B. L., Taylor, J. M. 2012; 85 (2)
  • Exploring models of associative memory via cavity quantum electrodynamics PHILOSOPHICAL MAGAZINE Gopalakrishnan, S., Lev, B. L., Goldbart, P. M. 2012; 92 (1-3): 353-361
  • Frustration and Glassiness in Spin Models with Cavity-Mediated Interactions PHYSICAL REVIEW LETTERS Gopalakrishnan, S., Lev, B. L., Goldbart, P. M. 2011; 107 (27)


    We show that the effective spin-spin interaction between three-level atoms confined in a multimode optical cavity is long-ranged and sign changing, like the RKKY interaction; therefore, ensembles of such atoms subject to frozen-in positional randomness can realize spin systems having disordered and frustrated interactions. We argue that, whenever the atoms couple to sufficiently many cavity modes, the cavity-mediated interactions give rise to a spin glass. In addition, we show that the quantum dynamics of cavity-confined spin systems is that of a Bose-Hubbard model with strongly disordered hopping but no on-site disorder; this model exhibits a random-singlet glass phase, absent in conventional optical-lattice realizations. We briefly discuss experimental signatures of the realizable phases.

    View details for DOI 10.1103/PhysRevLett.107.277201

    View details for Web of Science ID 000298611000018

    View details for PubMedID 22243326

  • Strongly Dipolar Bose-Einstein Condensate of Dysprosium PHYSICAL REVIEW LETTERS Lu, M., Burdick, N. Q., Youn, S. H., Lev, B. L. 2011; 107 (19)


    We report the Bose-Einstein condensation (BEC) of the most magnetic element, dysprosium. The Dy BEC is the first for an open f-shell lanthanide (rare-earth) element and is produced via forced evaporation in a crossed optical dipole trap loaded by an unusual, blue-detuned and spin-polarized narrowline magneto-optical trap. Nearly pure condensates of 1.5 × 10(4) (164)Dy atoms form below T = 30 nK. We observe that stable BEC formation depends on the relative angle of a small polarizing magnetic field to the axis of the oblate trap, a property of trapped condensates only expected in the strongly dipolar regime. This regime was heretofore only attainable in Cr BECs via a Feshbach resonance accessed at a high-magnetic field.

    View details for DOI 10.1103/PhysRevLett.107.190401

    View details for Web of Science ID 000297004600001

    View details for PubMedID 22181585

  • Dynamic polarizabilities and magic wavelengths for dysprosium PHYSICAL REVIEW A Dzuba, V. A., Flambaum, V. V., Lev, B. L. 2011; 83 (3)
  • Spectroscopy of a narrow-line laser-cooling transition in atomic dysprosium PHYSICAL REVIEW A Lu, M., Youn, S. H., Lev, B. L. 2011; 83 (1)
  • Dysprosium magneto-optical traps PHYSICAL REVIEW A Youn, S. H., Lu, M., Ray, U., Lev, B. L. 2010; 82 (4)
  • Atom-light crystallization of Bose-Einstein condensates in multimode cavities: Nonequilibrium classical and quantum phase transitions, emergent lattices, supersolidity, and frustration PHYSICAL REVIEW A Gopalakrishnan, S., Lev, B. L., Goldbart, P. M. 2010; 82 (4)
  • Anisotropic sub-Doppler laser cooling in dysprosium magneto-optical traps PHYSICAL REVIEW A Youn, S. H., Lu, M., Lev, B. L. 2010; 82 (4)
  • Cavity-Based Single Atom Preparation and High-Fidelity Hyperfine State Readout PHYSICAL REVIEW LETTERS Gehr, R., Volz, J., Dubois, G., Steinmetz, T., Colombe, Y., Lev, B. L., Long, R., Esteve, J., Reichel, J. 2010; 104 (20)


    We prepare and detect the hyperfine state of a single 87Rb atom coupled to a fiber-based high-finesse cavity on an atom chip. The atom is extracted from a Bose-Einstein condensate and trapped at the maximum of the cavity field, resulting in a reproducibly strong atom-cavity coupling. We use the cavity reflection and transmission signal to infer the atomic hyperfine state with a fidelity exceeding 99.92% in a readout time of 100  μs. The atom is still trapped after detection.

    View details for DOI 10.1103/PhysRevLett.104.203602

    View details for Web of Science ID 000277945900016

    View details for PubMedID 20867027

  • Trapping Ultracold Dysprosium: A Highly Magnetic Gas for Dipolar Physics PHYSICAL REVIEW LETTERS Lu, M., Youn, S. H., Lev, B. L. 2010; 104 (6)


    Ultracold dysprosium gases, with a magnetic moment 10 times that of alkali atoms and equal only to terbium as the most magnetic atom, are expected to exhibit a multitude of fascinating collisional dynamics and quantum dipolar phases, including quantum liquid crystal physics. We report the first laser cooling and trapping of half a billion Dy atoms using a repumper-free magneto-optical trap (MOT) and continuously loaded magnetic confinement, and we characterize the trap recycling dynamics for bosonic and fermionic isotopes. The first inelastic collision measurements in the few partial wave, 100 microK-1 mK, regime are made in a system possessing a submerged open electronic f shell. In addition, we observe unusual stripes of intra-MOT <10 microK sub-Doppler cooled atoms.

    View details for DOI 10.1103/PhysRevLett.104.063001

    View details for Web of Science ID 000274445100011

    View details for PubMedID 20366817

  • Powerful narrow-line source of blue light for laser cooling Yb/Er and Dysprosium atoms Conference on Solid State Lasers XIX - Technology and Devices Kobtsev, S., Lev, B., Fortagh, J., Baraulia, V. SPIE-INT SOC OPTICAL ENGINEERING. 2010

    View details for DOI 10.1117/12.841632

    View details for Web of Science ID 000284936100071

  • Emergent crystallinity and frustration with Bose-Einstein condensates in multimode cavities NATURE PHYSICS Gopalakrishnan, S., Lev, B. L., Goldbart, P. M. 2009; 5 (11): 845-850

    View details for DOI 10.1038/NPHYS1403

    View details for Web of Science ID 000271895500021

  • Biaxial nematic phases in ultracold dipolar Fermi gases NEW JOURNAL OF PHYSICS Fregoso, B. M., Sun, K., Fradkin, E., Lev, B. L. 2009; 11
  • Optical Interferometers with Reduced Sensitivity to Thermal Noise PHYSICAL REVIEW LETTERS Kimble, H. J., Lev, B. L., Ye, J. 2008; 101 (26)


    A fundamental limit to the sensitivity of optical interferometry is thermal noise that drives fluctuations in the positions of the surfaces of the interferometer's mirrors, and thereby in the phase of the intracavity field. Schemes for reducing this thermally driven phase noise are presented that rely upon the coherent character of the underlying displacements and strains. Although the position of the physical surface fluctuates, the optical phase upon reflection can have reduced sensitivity to this motion. While practical implementation of such schemes for coherent compensation face certain challenges, we hope to stimulate further work on this important thermal noise problem.

    View details for DOI 10.1103/PhysRevLett.101.260602

    View details for Web of Science ID 000262247100012

    View details for PubMedID 19437630

  • Loss of molecules in magneto-electrostatic traps due to nonadiabatic transitions PHYSICAL REVIEW A Lara, M., Lev, B. L., Bohn, J. L. 2008; 78 (3)
  • Mitigation of loss within a molecular Stark decelerator EUROPEAN PHYSICAL JOURNAL D Sawyer, B. C., Stuhl, B. K., Lev, B. L., Ye, J., Hudson, E. R. 2008; 48 (2): 197-209
  • Prospects for the cavity-assisted laser cooling of molecules PHYSICAL REVIEW A Lev, B. L., Vukics, A., Hudson, E. R., Sawyer, B. C., Domokos, P., Ritsch, H., Ye, J. 2008; 77 (2)
  • Magnetoelectrostatic trapping of ground state OH molecules PHYSICAL REVIEW LETTERS Sawyer, B. C., Lev, B. L., Hudson, E. R., Stuhl, B. K., Lara, M., Bohn, J. L., Ye, J. 2007; 98 (25)


    We report magnetic confinement of neutral, ground state OH at a density of approximately 3 x 10(3) cm(-3) and temperature of approximately 30 mK. An adjustable electric field sufficiently large to polarize the OH is superimposed on the trap in various geometries, making an overall potential arising from both Zeeman and Stark effects. An effective molecular Hamiltonian is constructed, with Monte Carlo simulations accurately modeling the observed single-molecule dynamics in various trap configurations. Magnetic trapping of cold polar molecules under adjustable electric fields may enable study of low energy dipolar interactions.

    View details for DOI 10.1103/PhysRevLett.98.253002

    View details for Web of Science ID 000247469400017

    View details for PubMedID 17678020

  • OH hyperfine ground state: From precision measurement to molecular qubits PHYSICAL REVIEW A Lev, B. L., Meyer, E. R., Hudson, E. R., Sawyer, B. C., Bohn, J. L., Ye, J. 2006; 74 (6)
  • Integration of fiber-coupled high-Q SiNx microdisks with atom chips APPLIED PHYSICS LETTERS Barclay, P. E., Srinivasan, K., Painter, O., Lev, B., Mabuchi, H. 2006; 89 (13)

    View details for DOI 10.1063/1.2356892

    View details for Web of Science ID 000240875800008

  • Quantum information processing in optical lattices and magnetic microtraps FORTSCHRITTE DER PHYSIK-PROGRESS OF PHYSICS Treutlein, P., Steinmetz, T., Colombe, Y., Lev, B., Hommelhoff, P., Reichel, J., Greiner, M., Mandel, O., Widera, A., Rom, T., Bloch, I., Hansch, T. W. 2006; 54 (8-10): 702-718
  • Precision measurement based on ultracold atoms and cold molecules 20th International Conference on Atomic Physics Ye, J., Blatt, S., Boyd, M. M., Foreman, S. M., Hudson, E. R., Ido, T., Lev, B., Ludlow, A. D., Sawyer, B. C., Stuhl, B., Zelevinsky, T. AMER INST PHYSICS. 2006: 80–91
  • Proposed magnetoelectrostatic ring trap for neutral atoms PHYSICAL REVIEW A Hopkins, A., Lev, B., Mabuchi, H. 2004; 70 (5)
  • Feasibility of detecting single atoms using photonic bandgap cavities Nanoscale Devices and System Integration Conference (NDSI-2004) Lev, B., Srinivasan, K., Barclay, P., Painter, O., Mabuchi, H. IOP PUBLISHING LTD. 2004: S556–S561
  • Fabrication of micro-magnetic traps for cold neutral atoms QUANTUM INFORMATION & COMPUTATION Lev, B. 2003; 3 (5): 450-464
  • Atom mirror etched from a hard drive APPLIED PHYSICS LETTERS Lev, B., Lassailly, Y., Lee, C., Scherer, A., Mabuchi, H. 2003; 83 (2): 395-397

    View details for DOI 10.1063/1.1592305

    View details for Web of Science ID 000184038900064

  • QUANTUM NETWORKS BASED ON CAVITY QED QUANTUM INFORMATION & COMPUTATION Mabuchi, H., Armen, M., Lev, B., Loncar, M., Vuckovic, J., Kimble, H. J., Preskill, J., Roukes, M., Scherer, A., van Enk, S. J. 2001; 1: 7-12
  • Radiation hardness evaluation of the Analog Devices AD9042 ADC for use in the CMS electromagnetic calorimeter NUCLEAR INSTRUMENTS & METHODS IN PHYSICS RESEARCH SECTION A-ACCELERATORS SPECTROMETERS DETECTORS AND ASSOCIATED EQUIPMENT Denes, P., Lev, B., Wixted, R. 1998; 417 (2-3): 371-376