Séminaire du LPTMS: Sylvain Nascimbène (LKB)

Synthetic quantum Hall system with ultracold Dysprosium atoms

Sylvain Nascimbène (LKB)

A quantum Hall system is characterized by the quantization of its Hall conductance, and its robustness with respect to material imperfections. In solid states devices disorder induces strong inhomogeneities in the Hall current distribution, making the connection with simple disorder-free models challenging. In this talk I will present the realization of a synthetic quantum Hall system using ultracold atoms of Dysprosium, in which a synthetic dimension is encoded in the electronic spin J=8. Dynamics in this dimension is induced by laser-induced spin couplings, and the Doppler effect occuring in these processes leads to a spin-orbit coupling, interpreted as an artificial magnetic field. We show that our system reproduces several characteristic features of Landau levels. We observe a clear distinction between bulk states — with inhibited motion due to limited energy dispersion — and edge modes, free to move in one direction only. We also probe the system excitations, via the measurement of cyclotron and skipping orbits. We finally probe the Hall response of the system, and make the connection to topological properties of the lowest energy band.

Date/Time : 08/10/2019 - 11:00 - 12:00

Location : Salle des séminaires du FAST et du LPTMS, bâtiment Pascal n°530