Topological aspects of π phase winding junctions in superconducting wires

Research output: Contribution to journalResearch articleContributedpeer-review

Contributors

  • Christian Spånslátt - , Stockholm University (Author)
  • Eddy Ardonne - , Stockholm University (Author)
  • Jan Carl Budich - , Austrian Academy of Sciences, University of Innsbruck (Author)
  • T. H. Hansson - , Stockholm University (Author)

Abstract

We theoretically investigate Josephson junctions with a phase shift of π in various proximity induced one-dimensional superconductor models. One of the salient experimental signatures of topological superconductors, namely the fractionalized periodic Josephson effect, is closely related to the occurrence of a characteristic zero energy bound state in such junctions. We make a detailed analysis of a more general type of π-junctions coined 'phase winding junctions' where the phase of the order parameter rotates by an angle π while its absolute value is kept finite. Such junctions have different properties, also from a topological viewpoint, and there are no protected zero energy modes. We compare the phenomenology of such junctions in topological (p-wave) and trivial (s-wave) superconducting wires, and briefly discuss possible experimental probes. Furthermore, we propose a topological field theory that gives a minimal description of a wire with defects corresponding to π-junctions. This effective theory is a one-dimensional version of similar theories describing Majorana bound states in half-vortices of two-dimensional topological superconductors.

Details

Original languageEnglish
Article number405701
JournalJournal of Physics Condensed Matter
Volume27
Issue number40
Publication statusPublished - 24 Sept 2015
Peer-reviewedYes
Externally publishedYes

Keywords

Keywords

  • Josephson junction, Kitaev wire model, topological superconductivity

Library keywords