Open-system many-body dynamics through interferometric measurements and feedback

TL;DR

This paper introduces a method to engineer driven-dissipative many-body quantum systems using interferometric measurements and feedback, enabling complex entanglement and interactions without intrinsic geometric constraints.

Contribution

It derives a feedback master equation for non-interacting systems that results in effective many-body quantum dynamics with pairwise interactions and collective dissipation.

Findings

Derivation of a general class of driven-dissipative many-body models

Identification of conditions for non-trivial quantum dynamics beyond local operations

Examples of stationary entanglement and emulation of dissipative Ising models

Abstract

Light-matter interfaces enable the generation of entangled states of light and matter which can be exploited to steer the quantum state of matter through measurement of light and feedback. Here we consider continuous-time, interferometric homodyne measurements of light on an array of light-matter interfaces followed by local feedback acting on each material system individually. While the systems are physically non-interacting, the feedback master equation we derive describes driven-dissipative, interacting many-body quantum dynamics, and comprises pairwise Hamiltonian interactions and collective jump operators. We characterize the general class of driven-dissipative many body systems which can be engineered in this way, and derive necessary conditions on models supporting non-trivial quantum dynamics beyond what can be generated by local operations and classical communication. We provide specific examples of models which allow for the creation of stationary many-particle entanglement, and the emulation of dissipative Ising models. Since the interaction between the systems is mediated via feedback only, there is no intrinsic limit on the range or geometry of the interaction, making the scheme quite versatile.