Micro-mechanical oscillator ground state cooling via intracavity optical atomic excitations

TL;DR

This paper proposes a novel method for ground state cooling of a micro-mechanical oscillator using resonant coupling to atomic excitations within an optical cavity, enabling efficient vibrational energy removal without requiring high finesse cavities.

Contribution

It introduces a new cavity cooling scheme leveraging atomic internal transitions and collective spin models, effective even with low finesse and small cavity volumes.

Findings

Predicted ground state cooling of a micro-mechanical oscillator.

Demonstrated suppression of reheating through tailored loss and gain channels.

Applicable to various cavity-based atomic and molecular cooling schemes.

Abstract

We predict ground state cooling of a micro-mechanical oscillator, i.e. a vibrating end-mirror of an optical cavity, by resonant coupling of mirror vibrations to a narrow internal optical transition of an ensemble of two level systems. The particles represented by a collective mesoscopic spin model implement, together with the cavity, an efficient, frequency tailorable zero temperature loss channel which can be turned to a gain channel of pump. As opposed to the case of resolved-sideband cavity cooling requiring a small cavity linewidth, one can work here with low finesses and very small cavity volumes to enhance the light mirror and light atom coupling. The tailored loss and gain channels provide for efficient removal of vibrational quanta and suppress reheating. In a simple physical picture of sideband cooling, the atoms shape the cavity profile to enhance/inhibit scattering into higher/lower energy sidebands. The method should be applicable to other cavity based cooling schemes for atomic and molecular gases as for molecular ensembles coupled to stripline cavities.