Academy of Finland  
Funding decision
Organisation Aalto University
Project title Vacuum forces between superconductors probed with microwave optomechanics
Applicant / Contact person Mercier de Lepinay, Laure
Decision No. 338565
Decision date 03.06.2021
Funding period 01.09.2021 - 31.08.2024
Funding 267 030
Project description
Radiation pressure is often thought of as the force of impinging photons, the quanta of light, on a surface. Interestingly, in the total darkness, the simple existence of the field even devoid of any photon applies a small pressure on surfaces, which is an effect of its quantum fluctuations. This so-called vacuum force is revealed in a Casimir setup, where two mirrors face each other at a very close distance. Some wavelengths are forbidden in the space between the mirrors and the vacuum force on mirrors from the interior sides facing each other is reduced compared to that exerted on the exterior sides, which pulls the mirrors together. Surprisingly, this force has never been observed between superconducting mirrors, although it would give useful insight into the nature of vacuum forces. I propose to use two tiny, 100-nanometers-thick aluminum layers spaced by a thin vacuum gap, cooled at milli-Kelvin temperatures to reach superconductivity, and observe this effect for the first time.