Surface scattering effect and the stripe order in films of the superfluid $^3$He B phase

TL;DR

This paper investigates how surface scattering influences the stability of stripe order and quasiparticle excitations in thin superfluid 3He B phase films, revealing stable stripe phases and midgap states.

Contribution

It demonstrates the stability of stripe order in films with mixed surface scattering conditions using Ginzburg-Landau theory and numerical solutions of the Eilenberger equation.

Findings

Stripe order can be stable with mixed surface scattering conditions.

Midgap states emerge due to stripe structure, distinct from surface bound states.

Local density of states reflects the presence of midgap states.

Abstract

Surface scattering effects in thin films of the superfluid 3He B phase have been theoretically investigated, with an emphasis on the stability of the stripe order with spontaneous broken translational symmetry in the film plane and quasiparticle excitations in this spatially inhomogeneous phase. Based on the Ginzburg-Landau theory in the weak coupling limit, we have shown that the stripe order, which was originally discussed for a film with two specular surfaces, can be stable in a film with one specular and one diffusive surfaces which should correspond to superfluid 3He on a substrate. It is also found by numerically solving the Eilenberger equation that due to the stripe structure, a midgap state distinct from the surface Andreev bound state emerges and its signature is reflected in the local density of states.