Generalized quantum measurements with matrix product states: Entanglement phase transition and clusterization

TL;DR

This paper introduces a matrix product state-based method to study the dynamics of quantum lattice systems under continuous measurement, revealing an entanglement transition and measurement-induced particle clusterization.

Contribution

It develops a novel approach using matrix product states to analyze measurement effects on quantum systems, uncovering a phase transition and unique clustering phenomena.

Findings

Identified a transition from entangling to disentangling phases.

Discovered measurement-induced particle clusterization.

Highlighted differences at the phase boundary based on measurement parameters.

Abstract

We propose a method, based on matrix product states, for studying the time evolution of many-body quantum lattice systems under continuous and site-resolved measurement. Both the frequency and the strength of generalized measurements can be varied within our scheme, thus allowing us to explore the corresponding two-dimensional phase diagram. The method is applied to one-dimensional chains of nearest-neighbor interacting hard-core bosons. A transition from an entangling to a disentangling (area-law) phase is found. However, by resolving time-dependent density correlations in the monitored system, we find important differences between different regions at the phase boundary. In particular, we observe a peculiar phenomenon of measurement-induced particle clusterization that takes place only for frequent moderately strong measurements, but not for strong infrequent measurements.