Developing a MEMS gyroscope for measurement of intrinsic angular momentum of topological superfluid

Abstract

Despite its importance, the angular momentum of a condensed matter system is one of the least measured quantities. Many theories suggest that superfluid ${}^3He-A$ carries a macroscopic angular momentum originating from its order parameter structure, but the measurement is still absent. Furthermore, the prediction of its value varies from theory to theory, and this disagreement is called the angular momentum paradox. To resolve the paradox, we developed a prototype gyroscope that operates at low temperatures. We also estimated the ultimate sensitivity limit of the gyroscope in terms of minimum measurable angular momentum based on amplitude modulation and frequency modulation methods. Frequency modulation has an advantage over amplitude modulation based on our gyroscope.