We present an analysis of the cooling of a micro-mechanical resonator by means of measurements and back action. The measurements are performed via the coupling to a Cooper-pair box, and although the coupling does not lead to net cooling, the extraction of information and hence entropy from the system leads to a pure quantum state. Under suitable circumstances, the states become very close to coherent states, conditioned on the measurement record, and can hence be displaced to the oscillator ground state.
Cite
@article{arxiv.0906.1909,
title = {Cooling a micro-mechanical resonator to its ground state by measurement back-action},
author = {Christian Bergenfeldt and Klaus Molmer},
journal= {arXiv preprint arXiv:0906.1909},
year = {2013}
}