Pole Placement Approach to Coherent Passive Reservoir Engineering for Storing Quantum Information

TL;DR

This paper introduces a pole placement method using coherent feedback control to engineer decoherence free subsystems in quantum systems, enhancing quantum information storage capabilities.

Contribution

It presents a novel constructive feedback design approach for decoherence free subsystem engineering, overcoming limitations of open loop methods.

Findings

Effective synthesis of decoherence free modes from non-DFS components

Enhanced quantum information storage through feedback control

General dynamic feedback structure applicable to quantum systems

Abstract

Reservoir engineering is the term used in quantum control and information technologies to describe manipulating the environment within which an open quantum system operates. Reservoir engineering is essential in applications where storing quantum information is required. From the control theory perspective, a quantum system is capable of storing quantum information if it possesses a so-called decoherence free subsystem (DFS). This paper explores pole placement techniques to facilitate synthesis of decoherence free subsystems via coherent quantum feedback control. We discuss limitations of the conventional `open loop' approach and propose a constructive feedback design methodology for decoherence free subsystem engineering. It captures a quite general dynamic coherent feedback structure which allows systems with decoherence free modes to be synthesized from components which do not have such modes.