Andreev bound states in superconductor-barrier-superconductor junctions of Rarita-Schwinger-Weyl semimetals

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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 superconductor-barrier-superconductor configuration built with Rarita-Schwinger-Weyl semimetal, which features four bands crossing at a single nodal point. Assuming a homogeneous s-wave pairing in each superconducting region, and the barrier region created by applying a voltage of magnitude $V_0 $ across a piece of normal state semimetal, we apply the BdG formalism to compute the discrete energy spectrum $\varepsilon $ of the subgap Andreev bound states in the short-barrier regime. In contrast with the two-band semimetals studied earlier, we find upto four pairs of localized states (rather than one pair for two-band semimetals) in the thin-barrier limit, and each value of $\varepsilon $ has a complicated dependence on the phase difference $φ_{12} $ via cosine and sine functions, which cannot be determined analytically. These are artifacts of multi-band nodes hosting quasiparticles of pseudospin values greater than $1/2$. Using the bound state energies, we compute the Josephson current across the junction configuration.
format Preprint
id arxiv_https___arxiv_org_abs_2312_16164
institution arXiv
publishDate 2023
record_format arxiv
spellingShingle Andreev bound states in superconductor-barrier-superconductor junctions of Rarita-Schwinger-Weyl semimetals
Mandal, Ipsita
Superconductivity
Mesoscale and Nanoscale Physics
High Energy Physics - Theory
We consider a superconductor-barrier-superconductor configuration built with Rarita-Schwinger-Weyl semimetal, which features four bands crossing at a single nodal point. Assuming a homogeneous s-wave pairing in each superconducting region, and the barrier region created by applying a voltage of magnitude $V_0 $ across a piece of normal state semimetal, we apply the BdG formalism to compute the discrete energy spectrum $\varepsilon $ of the subgap Andreev bound states in the short-barrier regime. In contrast with the two-band semimetals studied earlier, we find upto four pairs of localized states (rather than one pair for two-band semimetals) in the thin-barrier limit, and each value of $\varepsilon $ has a complicated dependence on the phase difference $φ_{12} $ via cosine and sine functions, which cannot be determined analytically. These are artifacts of multi-band nodes hosting quasiparticles of pseudospin values greater than $1/2$. Using the bound state energies, we compute the Josephson current across the junction configuration.
title Andreev bound states in superconductor-barrier-superconductor junctions of Rarita-Schwinger-Weyl semimetals
topic Superconductivity
Mesoscale and Nanoscale Physics
High Energy Physics - Theory
url https://arxiv.org/abs/2312.16164