Triplet superconductivity in the Rashba$^4$ model

arXiv (Cornell University)

Abstract

The Rashba$^4$ model is a lattice model of interacting fermions with a tight-binding dispersion relation that exhibits four Rashba band crossing points at the same energy. The fermions interact weakly, by an on-site repulsion and an additional nearest-neighbour two-body interaction, which may be attractive or repulsive. We study this model when the Fermi energy is at or close to the band crossings, by a combination of renormalization group flow equations and mean-field theory. We find that the scattering processes between different Rashba points drive superconductivity of an unusual triplet type not found in models with a single Rashba point.

Authors 2

1. G. A. H. Schober Aachen Institute for Theoretical Solid State Physics

   RWTH Aachen University · Heidelberg University

   Affiliation as printed

   Institute for Theoretical Physics , Heidelberg University , Philosophenweg 19 , 69120 Heidelberg , Germany

   Institute for Theoretical Solid State Physics , RWTH Aachen University , 52074 Aachen , Germany

2. Manfred Salmhofer

   Heidelberg University

   Affiliation as printed

   Institute for Theoretical Physics , Heidelberg University , Philosophenweg 19 , 69120 Heidelberg , Germany