Driven-dissipative preparation of entangled states in cascaded quantum-optical networks

TL;DR

This paper explores how driven-dissipative dynamics in cascaded quantum networks can be harnessed to generate and control entangled states across multiple quantum systems, with potential applications in quantum communication.

Contribution

It introduces a scheme for preparing entangled states in cascaded quantum networks via dissipative processes, including explicit protocols for two-level systems and non-linear cavities.

Findings

Pure stationary states with quantum correlations can be achieved under specific conditions.

The scheme enables tuning between different multi-partite entangled states.

Non-Gaussian entangled dark states can be realized in cascaded cavity systems.

Abstract

We study the dissipative dynamics and the formation of entangled states in driven cascaded quantum networks, where multiple systems are coupled to a common unidirectional bath. Specifically, we identify the conditions under which emission and coherent reabsorption of radiation drives the whole network into a pure stationary state with non-trivial quantum correlations between the individual nodes. We illustrate this effect in more detail for the example of cascaded two-level systems, where we present an explicit preparation scheme that allows one to tune the whole network through "bright" and "dark" states associated with different multi-partite entanglement patterns. In a complementary setting consisting of cascaded non-linear cavities, we find that two cavity modes can be driven into a non-Gaussian entangled dark state. Potential realizations of such cascaded networks with optical and microwave photons are discussed.