Preparing and manipulating quantum states of mechanical resonators is a highly interdisciplinary undertaking that now receives enormous interest for its far-reaching potential in fundamental and applied science. Up to now, only nanoscale mechanical devices achieved operation close to the quantum regime. We report a new micro-optomechanical resonator that is laser cooled to a level of 30 thermal quanta. This is equivalent to the best nanomechanical devices, however, with a mass more than four orders of magnitude larger (43 ng versus 1 pg) and at more than two orders of magnitude higher environment temperature (5 K versus 30 mK). Despite the large laser-added cooling factor of 4,000 and the cryogenic environment, our cooling performance is not limited by residual absorption effects. These results pave the way for the preparation of 100-um scale objects in the quantum regime. Possible applications range from quantum-limited optomechanical sensing devices to macroscopic tests of quantum physics.
@article{arxiv.0901.1801,
title = {Demonstration of an ultracold micro-optomechanical oscillator in a cryogenic cavity},
author = {Simon Groeblacher and Jared B. Hertzberg and Michael R. Vanner and Garrett D. Cole and Sylvain Gigan and K. C. Schwab and Markus Aspelmeyer},
journal= {arXiv preprint arXiv:0901.1801},
year = {2013}
}