Phase-locked magnetoconductance oscillations as a probe of Majorana edge states

Abstract

We calculate the Andreev conductance of a superconducting ring interrupted by a flux-biased Josephson junction, searching for electrical signatures of circulating edge states. Two-dimensional pair potentials of spin-singlet d-wave and spin-triplet p-wave symmetry support, respectively, (chiral) Dirac modes and (chiral or helical) Majorana modes. These produce h/e-periodic magnetoconductance oscillations of amplitude \simeq (e^{2}/h)N^{-1/2}, measured via an N-mode point contact at the inner or outer perimeter of the grounded ring. For Dirac modes the oscillations in the two contacts are independent, while for an unpaired Majorana mode they are phase locked by a topological phase transition at the Josephson junction.

10 pages, 6 figures. New appendix on the gauge invariant discretization of the Bogoliubov-De Gennes equation. Accepted for publication in PRB

References in corpus (6)

• Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
• Topological Defects and Gapless Modes in Insulators and Superconductors
• Topological Phases of Noncentrosymmetric Superconductors: Edge States, Majorana Fermions, and the Non-Abelian Statistics
• Topological spin-current in non-centrosymmetric superconductors
• Scattering theory of chiral Majorana fermion interferometry
• Scattering theory of topological invariants in nodal superconductors

Cited by in corpus (4)

• Topological surface states in nodal superconductors
• Tunneling transport in NSN junctions made of Majorana nanowires across the topological quantum phase transition
• Two-impurity helical Majorana problem
• Josephson oscillations of chirality and identity in two-dimensional solitons in spin-orbit-coupled condensates