Evolution of edge states and critical phenomena in the Rashba superconductor with magnetization

Phys Rev Lett. 2012 Feb 24;108(8):087003. doi: 10.1103/PhysRevLett.108.087003. Epub 2012 Feb 23.

Abstract

We study Andreev bound states (ABS) and the resulting charge transport of a Rashba superconductor (RSC) where two-dimensional semiconductor (2DSM) heterostructures are sandwiched by spin-singlet s-wave superconductor and ferromagnet insulator. ABS becomes a chiral Majorana edge mode in the topological phase (TP). We clarify two types of quantum criticality about the topological change of ABS near a quantum critical point (QCP), whether or not ABS exists at QCP. In the former type, ABS has an energy gap and does not cross at zero energy in the nontopological phase. These complex properties can be detected by tunneling conductance between normal metal-RSC junctions.