Transport in quantum chains under strong monitoring

TL;DR

This paper investigates how strong monitoring affects transport in 1D quantum systems, revealing a transition from quantum to classical dynamics, the emergence of classical processes, and the loss of ballistic transport due to the quantum Zeno effect.

Contribution

It demonstrates the quantum origins of classical stochastic processes and analyzes the impact of strong monitoring on transport properties in quantum chains.

Findings

Quantum Zeno effect inhibits transport and causes localization.

Emergence of classical exclusion and inclusion processes from quantum models.

Passive monitoring cannot break time-reversal symmetry and reduces transport from ballistic to diffusive.

Abstract

We study the transport properties of quantum 1D systems under strong monitoring. The quantum Zeno effect inhibits transport and induces localization. Beyond the Zeno freezing and on long time scales, a new dynamics emerges in the form of a Markov process. Studying fermionic and bosonic chains under strong monitoring, we are able to identify the quantum origin of the classical exclusion process, inclusion process and a sub-class of the misanthrope process. Moreover, we show that passive monitoring cannot break time-reversal symmetry and that the transport generally loses its ballistic nature existing for weak measurements.