Disorder driven Thouless charge pump in a quasiperiodic chain

Abstract

Thouless charge pump enables a quantized transport of charge through an adiabatic evolution of the Hamiltonian exhibiting topological phase. While this charge pumping is known to be robust against the presence of weak disorder in the system, it often breaks down with the increase in disorder strength. In this work, however, we show that in a one dimensional Su-Schrieffer-Heeger lattice, a unit cell-wise staggered quasiperiodic disorder favors a quantized charge pump. Moreover, we show that such quantized Thouless charge pump is achieved by following the standard single cycle pumping protocol which usually leads to a breakdown of charge pump in other known models. This unusual property is found to be due to an emergence of a trivial gapped phase from a topological phase as the quasiperiodic disorder is tuned. This emergent gapped to gapped transition also allows us to propose a non-standard pumping scheme where a modulated disorder favors a quantized Thouless charge pump.