Talk on "Optical, mechanical and thermal properties of superfluid helium drops levitated in vacuum"

27.05.2019 14:00 - 15:00

by Charles Brown, Yale

Optomechanical systems, in which light interacts with the motion of an object, provide an avenue to study the quantum behavior of macroscopic objects. Several goals in the field of quantum optomechanics require a combination of low temperature, low optical loss, low mechanical loss and high-precision measurement. Superfluid helium, as an optomechanical element, offers a number of advantages in these regards: extremely low optical absorption, vanishing viscosity, high thermal conductivity, and the ability to cool itself efficiently via evaporation. In recent years, superfluid optomechanical devices have made considerable advances, but their performance tends to be limited by the materials with which the superfluid is in contact. To avoid these limits and take better advantage of the superfluid’s unique properties, we use magnetic levitation to suspend a drop of superfluid liquid helium in vacuum, in pursuit of using the drop's optical whispering gallery modes (WGMs) and its surface waves as an optomechanical system. In this talk, we present recent measurements of mm-scale superfluid drops that are magnetically levitated in high vacuum. In particular, we will describe the formation and trapping of the drops, their evaporative cooling in the trap to ~ 330 mK, the drops’ mechanical resonances, and their optical Mie resonances.

Host: M.Aspelmeyer

Schrödingerroom, 4th floor, Boltzmanngasse 5, 1090 Vienna