Coupling of a nano mechanical oscillator and an atomic three-level medium

TL;DR

This paper presents a theoretical study of coupling between an ultracold three-level atomic gas and a nano-mechanical mirror, demonstrating how atomic transparency and opto-mechanical sidebands can control mirror vibrations.

Contribution

It introduces a novel mechanism for coupling atomic media with nano-mechanical oscillators via electromagnetic radiation, enabling phase-locked control of mirror vibrations.

Findings

Mirror vibrations can be resonantly driven by atomic sidebands.

Phase relations enable amplification or damping of vibrations.

Potential for cavity-free cooling of nano-mechanical oscillators.

Abstract

We theoretically investigate the coupling of an ultracold three-level atomic gas and a nano-mechanical mirror via classical electromagnetic radiation. The radiation pressure on the mirror is modulated by absorption of a probe light field, caused by the atoms which are electromagnetically rendered nearly transparent, allowing the gas to affect the mirror. In turn, the mirror can affect the gas as its vibrations generate opto-mechanical sidebands in the control field. We show that the sidebands cause modulations of the probe intensity at the mirror frequency, which can be enhanced near atomic resonances. Through the radiation pressure from the probe beam onto the mirror, this results in resonant driving of the mirror. Controllable by the two photon detuning, the phase relation of the driving to the mirror motion decides upon amplification or damping of mirror vibrations. This permits direct phase locking of laser amplitude modulations to the motion of a nano-mechanical element opening a perspective for cavity-free cooling through coupling to an atomic gas.