Superfluid He-3 suppression near atomically smooth surfaces

Quasiparticle scattering on surfaces is an important mechanism of pairbreaking of unconventional superfluids, and is particularly relevant for superfluids confined to small volumes. Typically, smooth atomic surfaces are thought to be minimally pairbreaking for superfluid He-3 A-phase in thin slabs. We consider scattering on smooth surfaces with lattice periodicity on the order of the Fermi wavelength of He-3, where diffraction effects may lead to strong back-scattering of quasiparticles and significant suppression of the transition temperature. We investigate how the periodic structure and the electronic density corrugation of the surface atomic layer affect the superfluid transition temperature in thin slabs.