Interaction induced splitting of Dirac monopoles in the topological Thouless pumping of strongly interacting Bosons and SU($N$) Fermions

TL;DR

This paper investigates how strong interactions affect topological quantization in the Thouless pump, revealing that interaction-induced monopole splitting alters the pump's quantization in strongly interacting bosons and fermions.

Contribution

It demonstrates how strong interactions modify Dirac monopoles in the topological pump, providing a theoretical explanation for the breakdown of quantization observed experimentally.

Findings

Interaction splits Dirac monopoles in the generalized Brillouin zone.

Quantization of the Thouless pump is governed by the Chern number.

Predicted charge pump behavior in strongly interacting Bose and SU(N) Fermi gases.

Abstract

Motivated by the observation of the breakdown of quantization for the Thouless pump in the presence of strong interaction by ETH [Walter et. al. Nat. Phys. 19, 1471 (2023), Viebahn et. al. arXiv:2308.03756], we study the interplay of strong interaction and topology in the (1+1)-dimensional interacting Rice-Mele model. We point out that the quantization of the interacting Thouless pump is dictated by the Chern number, i.e., the Dirac monopoles enclosed by the generalized Brillouin zone of the many-body wave function. By analyzing the change of location monopoles due to interaction, we predict the Thouless charge pump for strongly interacting Bose and SU($N$) Fermi gases in optical lattices and explain the ETH experiment.