Uncovering measurement-induced entanglement via directional adaptive dynamics and incomplete information

TL;DR

This paper presents a method to replicate the entanglement dynamics of monitored quantum systems using a measurement-free dissipative setup with directional interactions, enabling easier observation of entanglement transitions.

Contribution

It introduces a general recipe for mimicking conditional entanglement dynamics in measurement-free systems through directional interactions and auxiliary modes.

Findings

Demonstrates a bosonic system with entanglement-measurement competition

Shows how to implement measurement-feedforward dynamics autonomously

Discusses extensions to qubit and many-body systems

Abstract

The rich entanglement dynamics and transitions exhibited by monitored quantum systems typically only exist in the conditional state, making observation extremely difficult. In this work we construct a general recipe for mimicking the conditional entanglement dynamics of a monitored system in a corresponding measurement-free dissipative system involving directional interactions between the original system and a set of auxiliary register modes. This mirror setup autonomously implements a measurement-feedforward dynamics that effectively retains a coarse-grained measurement record. We illustrate our ideas in a bosonic system featuring a competition between entangling measurements and local unitary dynamics, and also discuss extensions to qubit systems and truly many-body systems.