Routing thermal noise through quantum networks

TL;DR

This paper demonstrates how to control thermal noise flow in quantum networks using a three-port device acting as a thermal transistor, enhancing the resilience of quantum devices and utilizing thermal noise as a resource.

Contribution

It introduces a non-reciprocal thermal noise routing mechanism in quantum networks using cascaded systems formalism, with a practical optomechanical implementation.

Findings

A three-port device can function as a thermal transistor.

Thermal noise can be directed towards or away from quantum devices.

The formalism maps onto experimentally feasible optomechanical systems.

Abstract

There is currently significant interest in operating devices in the quantum regime, where their behaviour cannot be explained through classical mechanics. Quantum states, including entangled states, are fragile and easily disturbed by excessive thermal noise. Here we address the question of whether it is possible to create non-reciprocal devices that encourage the flow of thermal noise towards or away from a particular quantum device in a network. Our work makes use of the cascaded systems formalism to answer this question in the affirmative, showing how a three-port device can be used as an effective thermal transistor, and illustrates how this formalism maps onto an experimentally-realisable optomechanical system. Our results pave the way to more resilient quantum devices and to the use of thermal noise as a resource.