Equal contribution of even and odd frequency pairing to transport across normal metal-superconductor junctions

Fuente: arXiv
Enregistré dans:
Détails bibliographiques
Auteurs principaux: Tamura, Shun, Kornich, Viktoriia, Trauzettel, Björn
Format: Preprint
Publié: 2023
Sujets:
Accès en ligne:
Tags: Ajouter un tag
Pas de tags, Soyez le premier à ajouter un tag!
_version_ 1866916250775453696
author Tamura, Shun
Kornich, Viktoriia
Trauzettel, Björn
author_facet Tamura, Shun
Kornich, Viktoriia
Trauzettel, Björn
contents Odd-frequency pairing is an unconventional type of Cooper pairing in superconductors related to the frequency dependence of the corresponding anomalous Green function. We show by a combination of analytical and numerical methods that odd-frequency pairing is ubiquitously present in the current of Andreev-scattered particles across a junction formed by a normal metal (N) and a superconductor (S), even if the superconducting pairing is of conventional $s$-wave, spin singlet type. We carefully analyze the conductance of NS junctions with different pairing symmetries ($s$-wave, $p$-wave, $d$-wave). In all cases, we identify a generic equal balance of even and odd frequency pairing to the contributions related to Andreev reflection. This analysis shows in retrospect that the presence of odd-frequency pairing in electric currents across NS junctions is rather the rule, not the exception. This insight stems from an alternative approach of analyzing the transport problem of hybrid structures. It is based on the Kubo-Greenwood formula with direct access to symmetries of the anomalous Green functions characterizing the superconducting pairing. We expect that our predictions substantially enrich the interpretation of transport data across NS junctions in many material combinations.
format Preprint
id arxiv_https___arxiv_org_abs_2309_05623
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Equal contribution of even and odd frequency pairing to transport across normal metal-superconductor junctions
Tamura, Shun
Kornich, Viktoriia
Trauzettel, Björn
Superconductivity
Mesoscale and Nanoscale Physics
Odd-frequency pairing is an unconventional type of Cooper pairing in superconductors related to the frequency dependence of the corresponding anomalous Green function. We show by a combination of analytical and numerical methods that odd-frequency pairing is ubiquitously present in the current of Andreev-scattered particles across a junction formed by a normal metal (N) and a superconductor (S), even if the superconducting pairing is of conventional $s$-wave, spin singlet type. We carefully analyze the conductance of NS junctions with different pairing symmetries ($s$-wave, $p$-wave, $d$-wave). In all cases, we identify a generic equal balance of even and odd frequency pairing to the contributions related to Andreev reflection. This analysis shows in retrospect that the presence of odd-frequency pairing in electric currents across NS junctions is rather the rule, not the exception. This insight stems from an alternative approach of analyzing the transport problem of hybrid structures. It is based on the Kubo-Greenwood formula with direct access to symmetries of the anomalous Green functions characterizing the superconducting pairing. We expect that our predictions substantially enrich the interpretation of transport data across NS junctions in many material combinations.
title Equal contribution of even and odd frequency pairing to transport across normal metal-superconductor junctions
topic Superconductivity
Mesoscale and Nanoscale Physics
url https://arxiv.org/abs/2309.05623