Special CPM Seminar

Quantum optomechanics with superfluid helium

Alexey Shkarin

Yale University

The field of optomechanics deals with interaction between light and mechanical objects. One of the important challenges in the field is manipulation of a mechanical state with a quantum precision, which allows for creation of interesting quantum states of mechanical objects and interfacing them with light or microwave radiation without significant information loss. In achieving this goal, one generally benefits from low mechanical losses, operation at low temperature, and large coupling between optical and mechanical systems. Superfluid helium is a liquid which is uniquely well-fit to meet these requirements.

In this talk I will describe our work on coupling infrared light to a standing acoustic wave in superfluid helium in a cavity optomechanics setting. In these experiments we were able to use light to coherently excite acoustic vibrations, manipulate their frequency and damping rate, and measure their thermal motion at effective temperatures as low as 100 mK (only 10 times larger than their zero-point energy). The precision of these measurements is high enough to reveal quantum signatures in the motion of the density waves and in their interaction with optical radiation.