Microwave circuits and mechanical resonators: reservoir engineering in the quantum regime.
Francesco Massel, University of South-Eastern Norway
Weekly Theory Seminar.
In my talk, I will present some of our recent achievements concerning the physics of optomechanical systems in the microwave regime. I will show how, through the coherent manipulation of an electromagnetic cavity, it is possible to drive the degrees of freedom of mechanical resonators into the quantum regime.
I will first discuss how we have achieved a squeezed state with single-quadrature noise below the zero-point fluctuations for a nanodrum mechanical resonator . Subsequently, I will analyze how it is possible, with the same philosophy, to induce and measure two-mode squeezing —and therefore entanglement— for two nearly- macroscopic mechanical resonators .
The latter result represents, on the one hand, an important breakthrough from the fundamental perspective, demonstrating how macroscopic collective degrees of freedom can be driven into the quantum regime. At the same time, the stationary nature of the entanglement generated suggests new possibilities in the realm of the technological exploitation of quantum mechanics.
 J. M. Pirkkalainen, et al. Phys. Rev. Lett. 115, 243601 (2015).
 C. F. Ockeloen-Korppi, et al. Nature 556, 478 (2018).
(The slides will be available here)