Second quantization of open quantum systems in Liouville space

TL;DR

This paper introduces a second quantization framework in Liouville space for open quantum systems, enabling efficient treatment of mixed states and dissipation, with applications to quantum light interactions.

Contribution

It develops a novel second quantization approach directly at the density matrix level in Liouville space, reducing computational complexity for open quantum systems.

Findings

Efficient modeling of open quantum systems with mixed states.

Analysis of incoherent processes in quantum light interactions.

Linking Liouville space methods to phase-space descriptions.

Abstract

We present a theoretical framework based on second quantization in Liouville space to treat open quantum systems. We consider an ensemble of identical quantum emitters characterized by a discrete set of quantum states. The second quantization is performed directly at the level of density matrices, thereby significantly reducing the size of the Liouville space. In contrast to conventional Hilbert space techniques, statistically mixed states and dissipation are naturally incorporated. As a particular example of application, we study the effect of incoherent processes and statistical mixing of emitters' initial states in the interaction with quantum light. Moreover, we link our framework to a phase-space description of the dynamics, which can overcome the computational limitations of our method with the increasing number of particles.