Speaker
Description
Resolved-sideband cooling is a standard technique in cavity optomechanics enabling quantum control of mechanical motion, but its performance is ultimately limited by quantum backaction heating. This fundamental effect imposes a limit on the minimum achievable mechanical phonon number, establishing a finite-temperature floor regardless of the applied cooling strength.
In this talk, we generalize the semi-classical model for optomechanical cooling to describe universal cavity Hamiltonians incorporating both passive and active nonlinearities [1]. As a concrete demonstration, we analyze the simplest circuit optomechanical system that implements a nonlinear drive via a Josephson junction. Our analysis reveals that this active nonlinear drive can eliminate the residual heating backaction. We compare with a series of excellent recent works demonstrating an alternative optomechanical cooling scheme based on passive Kerr-cavity nonlinearities [2,3,4].
By successfully overcoming the finite-temperature floor that limits conventional schemes, our method paves the way for unprecedented quantum control over mechanical systems and establishes the experimental viability of zero-heating optomechanical cooling.
[1] S. Sengupta, et al., Optomechanical Cooling without Residual Heating, arXiv:2511.10318 (2025).
[2] D. Zoepfl, et al., Kerr enhanced backaction cooling in magnetomechanics, Phys. Rev. Lett. 130, 033601 (2023).
[3] N. Diaz-Naufal, et al., Kerr-enhanced optomechanical cooling in the unresolvedsideband regime, Phys. Rev. A 111, 053505 (2025).
[4] L. F. Deeg, et al., Optomechanical backaction in the bistable regime, Phys. Rev. Appl. 23, 014082 (2025).