Ultracold fermions in optical lattices: flavour-dependent Mott localization and universal Hall response

by Prof. Leonardo Fallani (University of Florence)

Wednesday 3 Dec 2025, 10:00 → 11:00 Europe/Zurich

OSGA/6a&b or teams

Quantum simulators based on neutral atoms trapped in optical lattices provide a technological platform for studying solid-state phenomena from an original perspective and with ample tunability of the system parameters. This approach allows for the realization of both fundamental models and states of matter with no counterpart in conventional materials. I will discuss some examples of recent developments in this field which are opened by the coherent manipulation of internal states in strongly interacting Fermi gases of 173Yb atoms. 

I will discuss the realization of multi-component SU(N) Fermi-Hubbard systems, where a coherent laser coupling between internal states can induce a controlled breaking of the global interaction symmetry and lead to a flavour-selective Mott localization [1], in connection with the physics arising in strongly correlated materials from the coupling of different orbitals. 

I will then discuss recent experiments where we have measured the Hall conductivity in interacting synthetic ladders, where the laser coupling implements the action of a strong external magnetic field on effectively charged particles. I will show a strong dependence of the Hall response upon changing atom-atom interactions and the emergence of a universal regime in the strongly interacting limit [2]. I will then discuss recent developments with the measurement of Hall voltages and Hall resistances [3], which provide a direct connection between cold-atom quantum simulators and the measurement of electric-like quantities in solid-state systems.

[1] D. Tusi et al., Nat. Phys. 18, 1201 (2022).

[2] T. Zhou et al., Science 381, 427 (2023).

[3] T. Zhou et al., Nat. Comm. 16, 10247 (2025).