Narrowband Optomechanical Refrigeration of a Chiral Bath
Jacob M. Taylor, Kim Seunghwi, Xu Xunnong, Gaurav Bahl
The transport of sound and heat, in the form of phonons, is fundamentally limited by disorder-induced scattering. In electronic and optical settings, introduction of chiral transport - in which carriers have unidirectional propagation - provides robustness against such disorder by preventing elastic backscattering. We propose a path for inducing robust phonon transport in the presence of disorder. Our approach uses optomechanical coupling to both mitigate the influence of disorder, and simultaneously induce chirality in the transport of phonons. Here, we employ high quality factor mechanical modes of a whispering gallery optomechanical resonator as a probe of bulk properties. We experimentally demonstrate the optically-induced gain-free reduction of intrinsic damping of a phonon mode, and a dramatic chiral asymmetry in the propagation of clockwise and ccw phonons. Fur- thermore, this passive mechanism is accompanied by a reduction in 1 heat load leading to optical cooling of the mechanics, with simultaneous linewidth reduction. This technique has the potential to improve the thermal limits of resonant mechanical sensors, which cannot be attained through conventional optomechanical cooling.
, Seunghwi, K.
, Xunnong, X.
and Bahl, G.
Narrowband Optomechanical Refrigeration of a Chiral Bath, Nature Communications, [online], https://doi.org/10.1038/s41467-017-00247-7
(Accessed December 4, 2023)