Spin-polarized edge currents and Majorana fermions in one- and two-dimensional topological superconductors
2015 (English)In: Physical Review B. Condensed Matter and Materials Physics, ISSN 1098-0121, E-ISSN 1550-235X, Vol. 92, no 21, 214501Article in journal (Refereed) PublishedText
We investigate the persistent currents, spin-polarized local density of states, and spectral functions of topological superconductors constructed by placing ferromagnetic impurities on top of an s-wave superconductor with Rashba spin-orbit interaction. We solve self-consistently for the superconducting order parameter and investigate both two-dimensional blocks and one-dimensional wires of ferromagnetic impurities, with the magnetic moments pointing both perpendicular and parallel to the surface. We find that the topologically protected edge states of ferromagnetic blocks give rise to spin-polarized edge currents, but that the total persistent current flows in opposite direction to what is expected from the dispersion relation of the edge states. We also show that the Majorana fermions at the end points of one-dimensional wires are spin polarized, which can be directly related to the spin polarization of the edge currents of two-dimensional blocks. Connections are also made to the physics of the Yu-Shiba-Rusinov states for zero-dimensional impurities.
Place, publisher, year, edition, pages
2015. Vol. 92, no 21, 214501
Condensed Matter Physics
IdentifiersURN: urn:nbn:se:uu:diva-270955DOI: 10.1103/PhysRevB.92.214501ISI: 000365773700002OAI: oai:DiVA.org:uu-270955DiVA: diva2:890868
FunderSwedish Research CouncilGöran Gustafsson Foundation for promotion of scientific research at Uppala University and Royal Institute of TechnologySwedish Foundation for Strategic Research EU, European Research Council, DM-321031