Cooling a micro-mechanical resonator by quantum back-action from a noisy   qubit
  We study the role of qubit dephasing in cooling a mechanical resonator by quantum back-action. With a superconducting flux qubit as a specific example, we show that ground-state cooling of a mechanical resonator can only be realized if the qubit dephasing rate is sufficiently low. 
Ying-Dan Wang, Yong Li, Fei Xue, C. Bruder, K. Semba