Cooling a mechanical resonator with nitrogen-vacancy centres using a room temperature excited state spin-strain interaction.
Cooling a mechanical resonator mode to a sub-thermal state has been a long-standing challenge in physics. This pursuit has recently found traction in the field of optomechanics in which a mechanical mode is coupled to an optical cavity. An alternate method is to couple the resonator to a well-controlled two-level system. Here we propose a protocol to dissipatively cool a room temperature mechanical resonator using a nitrogen-vacancy centre ensemble. The spin ensemble is coupled to the resonator through its orbitally-averaged excited state, which has a spin-strain interaction that has not been previously studied. We experimentally demonstrate that the spin-strain coupling in the excited state is 13.5±0.5 times stronger than the ground state spin-strain coupling. We then theoretically show that this interaction, combined with a high-density spin ensemble, enables the cooling of a mechanical resonator from room temperature to a fraction of its thermal phonon occupancy.
Department of Physics, Cornell University, Ithaca, New York 14853, USA.
E R
ER
MacQuarrie
Department of Physics, Cornell University, Ithaca, New York 14853, USA.
M
M
Otten
Center for Nanoscale Materials, Argonne National Laboratory, Argonne, Illinois 60439, USA.
S K
SK
Gray
School of Applied and Engineering Physics, Cornell University, Ithaca, New York 14853, USA.
G D
GD
Fuchs