Speaker
Description
Radiation pressure makes light a uniquely clean and flexible tool for controlling motion at the nanoscale. We use it to couple nanomechanical resonators into small networks, linked by laser-driven optomechanical 'springs' that can be programmed in situ. By modulating the laser fields, we can also break acoustic symmetries that normally constrain mechanical vibrations, in particular time-reversal symmetry. This creates a synthetic magnetic field for phonons: just as a magnetic field steers the motion of electrons, it drives vibrations around a loop in a chosen direction.
In this talk, I will present two recent experimental results. First, I will show how light-induced synthetic magnetism affects the thermal behaviour of a three-resonator loop. We track the flow of heat through the network by resolving correlations in the optically transduced Brownian motion of the resonators. When a non-trivial synthetic flux breaks time-reversal symmetry, we observe chiral circulation of thermal fluctuations around the loop. The resulting chiral heat currents enhance the cooling of a hot mode—offering a new control knob for nanoscale heat transport.
Second, moving beyond linear couplings, I will demonstrate how the Lorentzian line shape of an optical cavity produces nonlinear optical backaction that gives rise to a mechanical Duffing nonlinearity. Unlike intrinsic or electrostatically induced nonlinearities, this optical nonlinearity offers full control over the magnitude, sign and order of the nonlinear coefficients. It can also be strong, with critical amplitudes below one nanometre. This establishes cavity optomechanics as a versatile platform for engineering nonlinear dynamics, with potential applications in sensing and energy-efficient computing.
| I am the presenting author | No |
|---|---|
| If you are not the presenting author, please give the presenting author's name: | Jesse J. Slim |