Noise-enhanced quantum transport on a closed loop using quantum walks

TL;DR

This paper investigates how noise influences quantum transport efficiency on a closed loop, revealing that noise can enhance transport in small systems but hinder it in larger ones, with quantum effects playing a key role.

Contribution

It demonstrates the dual role of noise in quantum transport on a loop and identifies regimes where quantum effects enhance efficiency.

Findings

Noise enhances transport in small loops

Transport efficiency decreases with noise in larger loops

Quantum effects are responsible for enhancement in certain regimes

Abstract

We study the effect of noise on the transport of a quantum state from a closed loop of $n-$sites with one of the sites as a sink. Using a discrete-time quantum walk dynamics, we demonstrate that the transport efficiency can be enhanced with noise when the number of sites in the loop is small and reduced when the number of sites in the loop grows. By using the concept of measurement induced disturbance we identify the regimes in which genuine quantum effects are responsible for the enhanced transport.