Critical Velocity in the Presence of Surface Bound States in Superfluid ${}^3$He-B

Abstract

A microelectromechanical oscillator with a gap of 1.25 $\mu$m was immersed in superfluid ${}^3$He-B and cooled below 250 $\mu$K at various pressures. Mechanical resonances of its shear motion were measured at various levels of driving force. The oscillator enters into a nonlinear regime above a certain threshold velocity. The damping increases rapidly in the nonlinear region and eventually prevents the velocity of the oscillator from increasing beyond the critical velocity which is much lower than the Landau critical velocity. We propose that this peculiar nonlinear behavior stems from the escape of quasiparticles from the surface bound states into the bulk fluid.

5 pages, 4 figures

References in corpus (5)

• Classification of topological insulators and superconductors in three spatial dimensions
• Thermodynamic properties of thin films of superfluid 3He-A
• The critical velocity in the BEC-BCS crossover
• Symmetry Protected Topological Superfluid ${}^3$He-B
• Critical velocities in superfluids and the nucleation of vortices

Cited by in corpus (3)

• Damping of a micro-electromechanical oscillator in turbulent superfluid ${}^4$He: A novel probe of quantized vorticity in the ultra-low temperature regime
• New Phases of Superfluid ${}^3$He Confined in Aerogels
• Subgap in the surface bound states spectrum of Superfluid ${}^3$He-B with Rough Surface