Phase Diagram of the Topological Superfluid 3 He Confined in a Nanoscale Slab Geometry

Abstract

Confined Helium: Helium-3 ( ³ He) has superfluid phases closely related to topological insulators and topological superconductors. In geometrical confinement, ³ He is expected to support exotic excitations, but its phase diagram is largely unknown, as such measurements are experimentally challenging. Levitin et al. (p. 841 ) confine ³ He in a slab geometry of defined height and use nuclear magnetic resonance as a probe. As predicted by theory, the authors find that the confinement stabilizes some of the superfluid phases across a larger portion of the phase diagram with respect to the bulk and potentially provides a testbed for topological superfluidity.