Prof. Sylvain Nascimbene, Département de Physique, École normale superérieure, Paris Exploring quantum Hall physics with ultracold dysprosium atoms
Prof. Sylvain Nascimbène
Laboratoire Kastler Brossel, Collège de France, Paris
Ultracold atomic gases offer a versatile platform for exploring rich phenomena in
quantum matter. In particular, topological states akin to those found in the quantum
Hall effect can be engineered by simulating orbital magnetic fields—an approach
greatly facilitated by the use of synthetic dimensions.
In this talk, I will present our experimental realization of a quantum Hall system using
ultracold gases of dysprosium atoms. By leveraging the atom’s large internal spin
(J=8), we encode a synthetic dimension and couple it to atomic motion via
two-photon optical transitions, which generates an effective magnetic field. We
observe hallmark signatures of quantum Hall physics, including a quantized Hall
response and gapless, chiral edge modes.
I will then describe a more intricate experiment designed to probe spatial
entanglement by simulating the so-called entanglement Hamiltonian. Using the
Bisognano-Wichmann theorem—which relates the entanglement Hamiltonian to a
spatially deformed version of the original system—we implement this deformation
along the synthetic dimension.
Lastly, I will discuss our recent investigation into a topological phase transition,
induced by introducing an additional lattice potential. I will highlight the system’s
behavior in the critical regime and explore the emergent features associated with the
transition.
