title: Majorana bound states and nonlocal spin correlations in a quantum wire on an unconventional superconductor.
abstract: We study theoretically the proximity effect of a one-dimensional metallic quantum wire (in the absence of spin-orbit interaction) lying on top of an unconventional superconductor. Three different material classes are considered as a substrate: (i) a chiral superconductor in class D with broken time-reversal symmetry and a class DIII superconductor (ii) with and (iii) without a nontrivial Z(2) number. Interestingly, we find degenerate zero energy Majorana bound states at both ends of the wire for all three cases. They are unstable against spin-orbit interaction in case (i), while they are topologically protected by time-reversal symmetry in cases (ii) and (iii). Remarkably, we show that nonlocal spin correlations between the two ends of the wire can be simply controlled by a gate potential in our setup.
authors.affiliation: Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Sho
authors.initials: S
authors.lastname: Nakosai
authors.affiliation: Department of Physics, Stockholm University, Se-106 91 Stockholm, Sweden.
authors.forename: Jan Carl
authors.initials: JC
authors.lastname: Budich
authors.affiliation: Department of Applied Physics, Nagoya University, Aichi 464-8603, Japan.
authors.forename: Yukio
authors.initials: Y
authors.lastname: Tanaka
authors.affiliation: Institute for Theoretical Physics and Astrophysics, University of Würzburg, 97074 Würzburg, Germany.
authors.forename: Björn
authors.initials: B
authors.lastname: Trauzettel
authors.affiliation: Department of Applied Physics, University of Tokyo, Tokyo 113-8656, Japan and Correlated Electron Research Group (CERG) and Cross-Correlated Materials Research Group (CMRG), RIKEN Advanced Science Institute (ASI), Wako 351-0198, Japan and RIKEN Center for Emergent Matter Science, RIKEN, Wako 351-0198, Japan.
authors.forename: Naoto
authors.initials: N
authors.lastname: Nagaosa