Two-particle topological Thouless spin pump

TL;DR

This paper demonstrates that two interacting particles with spin exchange can simulate topological phenomena like edge states and Thouless pumping, using their spin degrees of freedom as a synthetic dimension.

Contribution

It introduces a novel approach to emulate topological properties in condensed matter using only two particles by mapping spatial degrees to spin states.

Findings

Existence of topologically protected edge spin states.

Mapping of the spin system to the SSH and Rice-Mele models.

Simulation of topological pumping with two particles.

Abstract

We show that two particles interacting via spin exchange exhibit topological features found in one-dimensional single particle lattice models. This is accomplished by absorbing all of the spatial degrees of freedom of the lattices into the spin degrees of freedom of the two particles. Comparing the spin system with the Su-Schrieffer-Heeger model, we show the existence of topologically protected edge spin states and establish the bulk-edge correspondence. Modifying the spin system with a chiral symmetry breaking term results in it resembling the Rice-Mele model and can therefore act as a Thouless spin pump of one of the particles when periodically and adiabatically driven. By using the spin states as a synthetic spatial dimension, we show two particles are enough to simulate well known topological properties in condensed matter physics.