Routing thermal noise flow and ground-state cooling in an optomechanical plaquette

TL;DR

This paper introduces a method to cool two mechanical resonators to their ground state by controlling thermal noise flow in an optomechanical system, independent of their initial temperatures.

Contribution

It presents a novel noise routing technique in a four-mode optomechanical plaquette that enables ground-state cooling through phase control, complementing existing dark-mode strategies.

Findings

Thermal noise flow can be fully suppressed by phase tuning.

Optimal cooling down to the ground state is achievable.

The method is adaptable for nonreciprocal phonon transport control.

Abstract

We propose an effective method for cooling two non-degenerate mechanical resonators by routing thermal noise flow in a four-mode optomechanical plaquette. The thermal noise flow between the mechanical resonators can be fully suppressed by addressing the overall loop phase in the plaquette, irrespective of their thermal temperatures. We find that optimal mechanical cooling, even down to the ground state, can be realized in this regime. The thermal noise routing, achieved by dissipation engineering at optomechanical interfaces, provides a valuable and complementary approach to conventional coherent dark-mode control theory. It can be generalized to nonreciprocal control of phonon transport and mechanical cooling, and may find applications in optomechanical networks with complex thermal environments.