Energy localization enhanced ground-state cooling of mechanical resonator from room temperature in optomechanics using a gain cavity

TL;DR

This paper introduces a novel gain cavity approach in optomechanics that enables direct ground-state cooling of a mechanical resonator at room temperature, bypassing the need for cryogenic cooling.

Contribution

It presents a counterintuitive energy flow mechanism involving a gain cavity that significantly enhances mechanical cooling and induces unconventional optical spring effects.

Findings

Achieved room-temperature ground-state cooling of mechanical resonator.

Demonstrated giant frequency shifts and optically induced damping.

Enabled pre-cooling free ground-state cooling without cryogenics.

Abstract

When a gain system is coupled to a loss system, the energy usually flows from the gain system to the loss one. We here present a counterintuitive theory for the ground-state cooling of the mechanical resonator in optomechanical system via a gain cavity. The energy flows first from the mechanical resonator into the loss cavity, then into the gain cavity, and finally localizes there. The energy localization in the gain cavity dramatically enhances the cooling rate of the mechanical resonator. Moreover, we show that unconventional optical spring effect, e.g., giant frequency shift and optically induced damping of the mechanical resonator, can be realized. Those feature a pre-cooling free ground-state cooling, i.e., the mechanical resonator in thermal excitation at room temperature can directly be cooled to its ground state. This cooling approach has the potential application for fundamental tests of quantum physics without complicated cryogenic setups.