Andreev bound states in Josephson junctions of semi-Dirac semimetals

Fuente: arXiv
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Main Author: Mandal, Ipsita
Format: Preprint
Published: 2023
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author Mandal, Ipsita
author_facet Mandal, Ipsita
contents We consider a Josephson junction built with the two-dimensional semi-Dirac semimetal, which features a hybrid of linear and quadratic dispersion around a nodal point. We model the weak link between the two superconducting regions by a Dirac delta potential because it mimics the thin-barrier-limit of a superconductor-barrier-superconductor configuration. Assuming a homogeneous pairing in each region, we set up the BdG formalism for electronlike and holelike quasiparticles propagating along the quadratic-in-momentum dispersion direction. This allows us to compute the discrete bound-state energy spectrum $\varepsilon $ of the subgap Andreev states localized at the junction. In contrast with the Josephson effect investigated for propagation along linearly dispersing directions, we find a pair of doubly degenerate Andreev bound states. Using the dependence of $\varepsilon $ on the superconducting phase difference $ϕ$, we compute the variation of Josephson current as a function of $ϕ$.
format Preprint
id arxiv_https___arxiv_org_abs_2401_00506
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Andreev bound states in Josephson junctions of semi-Dirac semimetals
Mandal, Ipsita
Superconductivity
Mesoscale and Nanoscale Physics
High Energy Physics - Theory
We consider a Josephson junction built with the two-dimensional semi-Dirac semimetal, which features a hybrid of linear and quadratic dispersion around a nodal point. We model the weak link between the two superconducting regions by a Dirac delta potential because it mimics the thin-barrier-limit of a superconductor-barrier-superconductor configuration. Assuming a homogeneous pairing in each region, we set up the BdG formalism for electronlike and holelike quasiparticles propagating along the quadratic-in-momentum dispersion direction. This allows us to compute the discrete bound-state energy spectrum $\varepsilon $ of the subgap Andreev states localized at the junction. In contrast with the Josephson effect investigated for propagation along linearly dispersing directions, we find a pair of doubly degenerate Andreev bound states. Using the dependence of $\varepsilon $ on the superconducting phase difference $ϕ$, we compute the variation of Josephson current as a function of $ϕ$.
title Andreev bound states in Josephson junctions of semi-Dirac semimetals
topic Superconductivity
Mesoscale and Nanoscale Physics
High Energy Physics - Theory
url https://arxiv.org/abs/2401.00506