1304.0981 (Kristofer Björnson et al.)

Vortex states and Majorana fermions in spin-orbit coupled
semiconductor-superconductor hybrid structures    [PDF]

Kristofer Björnson, Annica M. Black-Schaffer

We study the energy spectrum of a vortex core in a two-dimensional semiconductor with Rashba spin-orbit interaction and proximity-coupled to a conventional superconductor and a ferromagnetic insulator. We perform self-consistent calculations using the microscopic tight-binding Bogoliubov-de Gennes method on a lattice and confirm the existence of Majorana fermions in the non-trivial topological phase. We also find two different topologically trivial superconducting phases, only differing in the type of vortex core structure they support and separated by a normal fermionic zero-energy excitation. Furthermore, we find an asymmetry in the energy spectrum with respect to both Zeeman splitting and vortex rotation direction and explain its physical origin.

View original: http://arxiv.org/abs/1304.0981