Stabilization of Hubbard-Thouless pumps through nonlocal fermionic repulsion

TL;DR

This paper demonstrates that nonlocal fermionic interactions can restore quantized topological pumping in a generalized Rice-Mele model, revealing a new stabilization mechanism for Thouless pumps in interacting quantum systems.

Contribution

It introduces a novel mechanism where intersite interactions stabilize Thouless pumping, contrasting previous findings of breakdown due to onsite repulsion.

Findings

Large intersite interactions enable recovery of quantized pumping.

Stable topological transport is linked to a bond-order-wave phase.

Proposes an experimental setup with ultracold atoms in optical lattices.

Abstract

Thouless pumping represents a powerful concept to probe quantized topological invariants in quantum systems. We explore this mechanism in a generalized Rice-Mele Fermi-Hubbard model characterized by the presence of competing onsite and intersite interactions. Contrary to recent experimental and theoretical results, showing a breakdown of quantized pumping induced by the onsite repulsion, we prove that sufficiently large intersite interactions allow for an interaction-induced recovery of Thouless pumps. Our analysis further reveals that the occurrence of stable topological transport at large interactions is connected to the presence of a spontaneous bond-order-wave in the ground-state phase diagram of the model. Finally, we discuss a concrete experimental setup based on ultracold magnetic atoms in an optical lattice to realize the newly introduced Thouless pump. Our results provide a new mechanism to stabilize Thouless pumps in interacting quantum systems.