Hybrid atom-membrane optomechanics

Abstract

Abstract. We report on the realization of a hybrid optomechanical system in which ultracold atoms are coupled to a micromechanical membrane. The atoms are trapped in the intensity maxima of an optical standing wave formed by retroreflection of a laser beam from the membrane surface. Vibrations of the membrane displace the standing wave, thus coupling to the center-of-mass motion of the atomic ensemble. Conversely, atoms imprint their motion onto the laser light, thereby modulating the radiation pressure force on the membrane. In this way, the laser light mediates a long-distance coherent coupling between the two systems. When the trap frequency of the atoms is matched to the membrane frequency, we observe resonant energy transfer. Moreover, we demonstrate sympathetic damping of the membrane motion by coupling it to laser-cooled atoms. Theoretical investigations show that the coupling strength can be considerably enhanced by placing the membrane inside an optical cavity. This could lead to quantum coherent coupling and ground-state cooling of the membrane via a distant atomic ensemble.

Hybrid Mechanical Systems

“…Recently, a novel system was realized in which the spin of a nitrogen vacancy center in diamond was used to sense mechanical motion [47,48]. In another recent experiment, an ensemble of ultracold atoms in an optical lattice was optically coupled to vibrations of a micromechanical membrane [83,84], enabling sympathetic cooling of the membrane through laser-cooled atoms. By enhancing the coupling with a high-finesse cavity, strong coupling could be achieved even for a single atom [73].…”

“…Remarkably, some of these schemes predict strong atom-oscillator coupling even for a single atom [73,74]. First experimental implementations of hybrid atom-oscillator systems have recently been reported [81][82][83][84]. In the following, we discuss several of these proposals and experiments (see also the review in [85]).…”

“…In contrast, an indirect coupling mechanism acting over some distance would allow to keep the atomic and the micromechanical system in separate environments. Such a scheme was suggested in [68,69] and experimentally implemented as described in [83,84].…”

Kevés szabadsági fokú kvantumrendszerek dinamikai tulajdonságai

“…A különböző nanoméretű oszcillátorok [181,182] megvalósítása például olyan szintre ért, hogy segítségükkel akár atomi nagyságrendű tömegeket is lehet mérni [183,184]. Nanomechanikai oszcillátorokhoz csatolhatjuk egy optikai rezonátor egy módusát (például egy membránon történő fényvisszaverődést kihasználva [185,186]), így optomechanikai csatolást létrehozva a két rendszer között [187,188]. Az optomechanikai rendszereknek gyakorlati alkalmazása lehet például, hogy ultrahideg atomokat egy membránhoz csatolva azt hűteni tudjuk [185,189].…”

Optomechanical laser cooling with mechanical modulations

“…In the simplest and most commonly used model a single mechanical harmonic oscillator is coupled to a single mode of an optical cavity by radiation pressure interaction being proportional to the light intensity. The prototype of an optomechanical setup is a Fabry-Perot cavity with pendular end-mirror, whose microfabricated realization [2], but also other implementations [3][4][5][6], have been developed in the laboratories worldwide. The optomechanical coupling allows for optical control of the mechanical object, manifesting itself in strongly modified mechanical properties what ultimately can lead to laser cooling [7][8][9] towards the mechanical ground state, as has been demonstrated in a certain setup [10], marking a requisite milestone on the way to quantum applications.…”