Ground-state cooling of a suspended nanowire through inelastic   macroscopic quantum tunneling in a current-biased Josephson junction
  We demonstrate that a suspended nanowire forming a weak link between two superconductors can be cooled to its motional ground state by a supercurrent flow. The predicted cooling mechanism has its origins in magnetic field induced inelastic tunneling of the macroscopic superconducting phase associated with the junction. Furthermore, we show the voltage-drop over the junction is proportional to the average population of the vibrational modes in the stationary regime, a phenomena which can be used to probe the level of cooling. 
Gustav Sonne and Leonid Y. Gorelik
cond-mat.mes-hall