Laser cooling of atoms uses radiation forces of light to push on atoms, and has revolutionized atomic physics. In our work, in a field known as optomechanics, we now have the capacity to cool vibrations of mesoscopic objects using radiation pressure combined with cryogenic cooling. We pick out particular nanomechanical modes of the solid that are well-isolated from their environment, and that we can control with light using an extremely-precise optical cavity.
With this capability we explore long-predicted quantum limits to interferometric sensing, and apply control of mechanical degree of freedom to quantum information processing. In our experiments, we work with mechanical drumlike membranes of SiN that oscillate at MHz frequencies. With these membranes we observed quantum backaction in an interferometric measurement of mechanical motion, i.e. radiation pressure shot noise, on our membrane microresonators. This realization subsequently led to exploration of strong optomechanical squeezing of light, and the use of quantum correlations to improve displacement detection.
We are now looking at the unique ramifications of cavity optomechanics and phononic-crystal membrane resonators for sensing.