Measuring angular momentum of p(x) + ip(y) topological superfluids: A proposal

Abstract

Topological superconductors are among the most actively studied materials these days. They are a promising candidate for hosting Majorana fermions either on their boundaries or in vortex cores. Detecting one-dimensional (1D) edge current around the periphery of a 2D p(x) + ip(y) superconductor would be a hallmark signature of topological superconductivity, but Majorana fermions are not amenable to electronic current measurements due to their charge-neutral nature. Thermal conductivity measurements, such as the thermal Hall effect, are alternatively proposed, but material synthesis must come first. Superfluid He-3-A, on the other hand, is a known px + ipy superfluid whose angular momentum generated by the edge current can be measured with a gyroscopic technique. Here, we propose a microelectromechanical system based gyroscope that will not only have enough signal sensitivity to measure the angular momentum but also be used to observe dimensionality induced phase transitions between different topological superfluids.