All Publications


  • 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

    Abstract

    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

  • 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

    Abstract

    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)