Francois Crépin | Searcharxiv

arXiv2014

Nonperturbative phase diagram of interacting disordered Majorana nanowires

We develop a Gaussian variational approach in replica space to investigate the phase diagram of a one-dimensional interacting disordered topological superconducting wire in the strong coupling regime. This method allows for a non-perturbative treatment in the disorder strength, electron- electron interactions and the superconducting pairing amplitude. We find only two stable phases: a topological superconducting phase, and a glassy, non-topological localized phase, characterized by replica symmetry breaking.

cond-mat.mes-hall↗

arXiv2014

Random Rashba spin-orbit coupling at the quantum spin Hall edge

We study a one-dimensional helical system with random Rashba spin-orbit coupling. Using renor- malization group methods, we derive a consistent set of flow equations governing the important con- trol parameters of the backscattering process. Thereby, we prove the existence of disorder-induced two-particle backscattering that can even be non-local in space. This analysis allows us to derive the scaling form of the conductance at low temperatures. We find that two-particle backscattering due to random spin-orbit coupling differs from the one off a single Rashba impurity by both the scaling of the conductance with the temperature and the relevance of the backscattering operators.

cond-mat.mes-hall↗