Affiliation
University of Basel
Title of work
RKKY interaction at helical edges of topological superconductors
Abstract
We study spin configurations of classical magnetic impurities placed close to the edge of a two-dimensional topological superconductor. First, we demonstrate that the spin of a single magnetic impurity close to the edge of a topological superconductor tends to align along the edge. The strong easy-axis spin anisotropy behind this effect originates from the interaction between the impurity and the gapless helical Majorana edge states. We then compute the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction between two magnetic impurities placed close to the edge.
We show that, in the limit of large inter-impurity distances, the RKKY interaction between the two impurities is mainly mediated by the Majorana edge states and leads to a ferromagnetic alignment of both spins along the edge. We argue that this effect can be used to detect helical Majorana edge states.