Soliton Pumping in the Rice-Mele Model with On-Cell Kerr Nonlinearity

TL;DR

This paper explores how on-cell Kerr nonlinearities in the Rice-Mele model influence topological soliton pumping, revealing regimes of quantized transport, disruption, and discrete time-translation symmetry breaking due to interactions.

Contribution

It introduces the analysis of nonlinear interactions in the Rice-Mele model, demonstrating their impact on topological soliton dynamics and revealing novel symmetry-breaking phenomena.

Findings

Quantized Thouless pumping in weak interactions

Disruption of quantized transport at intermediate interactions

Emergence of discrete time-translation symmetry breaking in strong interactions

Abstract

We investigate the Rice-Mele model with on-cell Kerr-type nonlinearities, where the interaction depends on the total particle number within each unit cell rather than on individual sites. This interaction enables a nontrivial interplay between topology and nonlinear dynamics in soliton pumping. In the weakly interacting regime, the ground-state soliton undergoes quantized Thouless pumping. At intermediate interaction strengths, soliton creation and annihilation break adiabaticity and disrupt quantized transport. In the strong-coupling regime, the coexistence of ground- and excited-state solitons leads to negligible coupling at energy crossings, giving rise to discrete time-translation symmetry breaking (DTTSB) in the soliton dynamics. Comparison of mean-field results with exact diagonalization along closed circular pumping paths confirms both the validity of the mean-field description and the robustness of DTTSB across different pumping trajectories. Our findings reveal how interaction-induced effects can fundamentally modify topological transport and suggest that these phenomena may be explored in cold-atom, photonic, and superconducting-circuit platforms.