On Transfer Function Realizations for Linear Quantum Stochastic Systems

TL;DR

This paper reviews two methods for realizing transfer functions in Linear Quantum Stochastic Systems, crucial for quantum control applications, involving cascaded optical networks and feedback configurations.

Contribution

It provides a comprehensive review of two novel realization techniques for LQSS transfer functions, enhancing practical implementation options.

Findings

Two realization methods are detailed: cascade and feedback network approaches.

Both methods facilitate practical implementation of quantum control systems.

The techniques improve the design flexibility for quantum optical networks.

Abstract

The realization of transfer functions of Linear Quantum Stochastic Systems (LQSSs) is an issue of fundamental importance for the practical applications of such systems, especially as coherent controllers for other quantum systems. In this paper, we review two realization methods proposed by the authors in [1], [2], [3], [4]. The first one uses a cascade of a static linear quantum-optical network and single-mode optical cavities, while the second uses a feedback network of such cavities, along with static linear quantum-optical networks that pre- and post-process the cavity network inputs and outputs.