Quantum reservoir for microwaves

EPFL researchers use a mechanical micrometer-size drum cooled close to the quantum ground state to amplify microwaves in a superconducting circuit. Image: Photograph of the chip used in the experiment to couple a microwave cavity to a micrometer-size drum (the sharp purple pencil tip is placed as a scale). Inset shows a scanning electron micrograph of the drum. The top membrane of the drum is suspended only 50nm (1/2000th of the diameter of hair) above a metal plate. This is then used to manipulate and amplify microwaves in the quantum regime. Credit: N. R. Bernier - and L. D.