David Moore Colloquium: Mechanical sensors for dark matter and neutrinos

The development of optomechanical systems—in which the motion of a massive object is controlled and measured using light—has revolutionized the detection of tiny forces over the past few decades. As such technologies reach, and even surpass, quantum measurement limits, they can enable new searches for extremely weakly coupled phenomena including dark matter, neutrinos, and possibly even gravitational interactions between quantum systems. As a demonstration of these techniques, I will describe an initial search for dark matter using optically levitated nanogram mass sensors, which can exceed the sensitivity of even large underground detectors for certain classes of dark matter in just a few days of operation. If a signal were detected, such sensors may be able to correlate its direction with earth’s motion through the galaxy, allowing definitive confirmation that such a signal arose from dark matter. In addition, I will discuss future applications of such sensors to neutrino physics in a table-top scale experiment. Results from a recent proof-of-principle measurement demonstrate that the force imparted by a single nuclear decay occurring within an optically levitated, dust-sized particle can be detected