# Disorder-induced dephasing in backscattering-free quantum transport

## TL;DR

This paper investigates how disorder affects quantum transport without backscattering, showing that dephasing is bounded and identifying conditions to maintain backscattering-free propagation despite disorder.

## Contribution

It provides a comprehensive analysis of disorder-induced dephasing in backscattering-free quantum transport using Lindblad master equations, including bounds and gap conditions.

## Key findings

- Dephasing due to disorder is bounded in backscattering-free transport.
- A gap condition ensures the regime remains backscattering-free despite disorder.
- The analysis includes full disorder-averaged quantum states, considering populations and coherences.

## Abstract

We analyze the disorder-perturbed transport of quantum states in the absence of backscattering. This comprises, for instance, the propagation of edge-mode wave packets in topological insulators, or the propagation of photons in inhomogeneous media. We quantify the disorder-induced dephasing, which we show to be bound. Moreover, we identify a gap condition to remain in the backscattering-free regime despite disorder-induced momentum broadening. Our analysis comprises the full disorder-averaged quantum state, on the level of both populations and coherences, appreciating states as potential carriers of quantum information. The well-definedness of states is guaranteed by our treatment of the nonequilibrium dynamics with Lindblad master equations.