Cyclotron Dynamics of a Kondo Singlet in a Spin-Orbit-Coupled Alkaline-Earth Atomic Gas

TL;DR

This paper proposes a method to observe the quantum spin Hall effect of Kondo singlets in ultracold alkaline-earth atomic gases, revealing novel spin-dependent cyclotron dynamics governed by an effective Harper-Hofstadter model.

Contribution

It introduces a scheme to study Kondo-exchange and quantum spin Hall effects in ultracold atomic gases, highlighting collective cyclotron dynamics of Kondo singlets in optical lattices.

Findings

Kondo singlet exhibits spin-dependent cyclotron orbits

Collective dynamics governed by an effective Harper-Hofstadter model

Demonstrates quantum spin Hall effect in ultracold atomic system

Abstract

We propose a scheme to investigate the interplay between Kondo-exchange interaction and quantum spin Hall effect with ultracold fermionic alkaline-earth atoms trapped in two-dimensional optical lattices using ultracold collision and laser-assisted tunneling. In the strong Kondo-coupling regime, though the loop trajectory of the mobile atom disappears, collective dynamics of an atom pair in two clock states can exhibit an unexpected spin-dependent cyclotron orbit in a plaquette, realizing the quantum spin Hall effect of the Kondo singlet. We demonstrate that the collective cyclotron dynamics of the spin-zero Kondo singlet is governed by an effective Harper-Hofstadter model in addition to second-order diagonal tunneling.