Fundamental Physics Tests with Precision Acoustic Sensors

Crystalline bulk acoustic wave (BAW) resonators provide a high precision architecture for fundamental physics experiments that search for signatures of beyond the standard model physics. In this work we present an overview of recent experiments that exploit the advantageous metrological properties of quartz BAW resonators in order to test quantum gravity, as well as search for high frequency gravitational waves. Utilizing these resonators, we have improved upon existing constraints on the scale of a discrete minimum length, as

proposed in several quantum descriptions of gravity, by several orders of magnitude. We have also developed a unique high frequency gravitational wave detector with competitive strain sensitivity to gravitational radiation in the MHz frequency band. When cooled to mK temperature modes in these devices will naturally be in their ground state, so the possibility exists to improve precision using quantum metrology.