# Revealing many-body effects on interband coherence through adiabatic charge pumping

## TL;DR

This paper explores how adiabatic charge pumping can reveal many-body interaction effects on interband coherence in a one-dimensional fermionic system, offering a new way to study quantum coherence dynamics.

## Contribution

It demonstrates that the pumped charge depends on interband coherence and shows how to observe many-body effects on quantum coherence through different pumping protocols.

## Key findings

- Interband coherence affects pumped charge depending on initial state.
- Adjusting switch-on rates reveals many-body interaction effects.
- Weak interactions lead to vanishing charge differences at coherence minima.

## Abstract

The adiabatic charge pumping of a non-equilibrium state of spinless fermions in a one-dimensional lattice is investigated, with an emphasis placed on its usefulness in revealing many-body interaction effects on interband coherence. For a non-interacting system, the pumped charge per adiabatic cycle depends not only on the topology of the occupied bands but also on the interband coherence in the initial state. This insight leads to an interesting opportunity for quantitatively observing how quantum coherence is affected by many-body interaction that is switched on for a varying duration prior to adiabatic pumping. In particular, interband coherence effects can be clearly observed by adjusting the switch-on rates with different adiabatic pumping protocols and by scanning the duration of many-body interaction prior to adiabatic pumping. The time dependence of single-particle interband coherence in the presence of many-body interaction can then be examined in detail. As a side but interesting result, for relatively weak interaction strength, it is found that the difference in the pumped charges between different pumping protocols vanishes if a coherence measure defined from the single-particle density matrix in the sublattice representation reaches its local minima. Our results hence provide an interesting means to quantitatively probe the dynamics of quantum coherence in the presence of many-body interaction (e.g., in a thermalization process).