Topological aspects of pi phase winding junctions in superconducting wires
Number of Authors: 4
2015 (English)In: Journal of Physics: Condensed Matter, ISSN 0953-8984, E-ISSN 1361-648X, Vol. 27, no 40, 405701Article in journal (Refereed) Published
We theoretically investigate Josephson junctions with a phase shift of pi in various proximity induced one-dimensional superconductor models. One of the salient experimental signatures of topological superconductors, namely the fractionalized 4 pi 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 pi-junctions coined 'phase winding junctions' where the phase of the order parameter rotates by an angle pi 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 p-junctions. This effective theory is a one-dimensional version of similar theories describing Majorana bound states in half-vortices of two-dimensional topological superconductors.
Place, publisher, year, edition, pages
2015. Vol. 27, no 40, 405701
topological superconductivity, Kitaev wire model, Josephson junction
IdentifiersURN: urn:nbn:se:su:diva-122927DOI: 10.1088/0953-8984/27/40/405701ISI: 000362554100007OAI: oai:DiVA.org:su-122927DiVA: diva2:871614