Low Frequency Approximation for a class of Linear Quantum Systems using Cascade Cavity Realization

TL;DR

This paper introduces a low-frequency approximation method for complex linear quantum systems composed of optical components, enabling simpler analysis while maintaining accuracy in the low-frequency range.

Contribution

It extends cascade realization techniques to approximate complex quantum systems, focusing on low-frequency behavior, which is novel in quantum control.

Findings

Provides accurate low-frequency approximations for quantum optical systems

Enables simplified analysis of complex quantum networks

Builds on previous cascade realization results

Abstract

This paper presents a method for approximating a class of complex transfer function matrices corresponding to physically realizable complex linear quantum systems. The class of linear quantum systems under consideration includes interconnections of passive optical components such as cavities, beam-splitters, phase-shifters and interferometers. This approximation method builds on a previous result for cascade realization and gives good approximations at low frequencies.