Topological pumping in the one-dimensional Bose-Hubbard model

TL;DR

This paper investigates topological quantum pumping in a strongly interacting one-dimensional Bose-Hubbard model using time-dependent density matrix renormalization group methods, revealing quantized charge transport and analyzing finite-size and non-adiabatic effects.

Contribution

It provides a detailed numerical analysis of topological pumping in an interacting bosonic system, including finite-size scaling and non-adiabatic corrections, which was not previously explored.

Findings

Pumped charge is quantized and topological.

Finite-size effects influence the quantization accuracy.

Non-adiabatic corrections depend on modulation frequency.

Abstract

By means of time-dependent density matrix renormalization group calculations we study topological quantum pumping in a strongly interacting system. The system under consideration is described by the Hamiltonian of a one-dimensional extended Bose-Hubbard model in the presence of a correlated hopping which breaks lattice inversion symmetry. This model has been predicted to support topological pumping [E. Berg, M. Levin, and E. Altman, Phys. Rev. Lett. 106, 110405 (2011)]. The pumped charge is quantized and of topological nature. We provide a detailed analysis of the finite-size-scaling behavior of the pumped charge and its deviations from the quantized value. Furthermore we also analyze the non-adiabatic corrections due to the finite frequency of the modulation. We consider two configurations: a closed ring where the time-dependence of the parameter induces a circulating current, and a finite open-ended chain where particles are dragged from one edge to the opposite edge, due to the pumping mechanism induced by the bulk.