Electronic structure of the surface superconducting Weyl semimetal PtBi$_2$

Fuente: arXiv
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Main Authors: Vocaturo, Riccardo, Koepernik, Klaus, Facio, Jorge I., Timm, Carsten, Fulga, Ion Cosma, Janson, Oleg, Brink, Jeroen van den
Format: Preprint
Published: 2024
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author Vocaturo, Riccardo
Koepernik, Klaus
Facio, Jorge I.
Timm, Carsten
Fulga, Ion Cosma
Janson, Oleg
Brink, Jeroen van den
author_facet Vocaturo, Riccardo
Koepernik, Klaus
Facio, Jorge I.
Timm, Carsten
Fulga, Ion Cosma
Janson, Oleg
Brink, Jeroen van den
contents Trigonal PtBi$_2$ is a layered semimetal without inversion symmetry, featuring 12 Weyl points in the vicinity of the Fermi energy. Its topological Fermi arcs were recently shown to superconduct at low temperatures where bulk superconductivity is absent. Here, we perform first-principles calculations to investigate in detail the bulk and surface electronic structure of PtBi$_2$, and obtain the spin texture as well as the momentum-dependent localization of the arcs. Motivated by the experimentally observed recovery of inversion symmetry under pressure or upon doping, we interpolate between the two structures and determine the energy and momentum dependence of the Weyl nodes. For deeper insights into the surface superconductivity of PtBi$_2$, we construct a symmetry-adapted effective four-band model that accurately reproduces the Weyl points of PtBi$_2$. We supplement this model with an analysis of the symmetry-allowed pairings between the Fermi arcs, which naturally mix spin-singlet and spin-triplet channels. Moreover, the presence of surface-only superconductivity facilitates an intrinsic superconductor-semimetal-superconductor Josephson junction, with the semimetallic phase sandwiched between the two superconducting surfaces. For a phase difference of $π$, zero-energy Andreev bound states develop between the two terminations.
format Preprint
id arxiv_https___arxiv_org_abs_2404_19606
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Electronic structure of the surface superconducting Weyl semimetal PtBi$_2$
Vocaturo, Riccardo
Koepernik, Klaus
Facio, Jorge I.
Timm, Carsten
Fulga, Ion Cosma
Janson, Oleg
Brink, Jeroen van den
Superconductivity
Mesoscale and Nanoscale Physics
Materials Science
Trigonal PtBi$_2$ is a layered semimetal without inversion symmetry, featuring 12 Weyl points in the vicinity of the Fermi energy. Its topological Fermi arcs were recently shown to superconduct at low temperatures where bulk superconductivity is absent. Here, we perform first-principles calculations to investigate in detail the bulk and surface electronic structure of PtBi$_2$, and obtain the spin texture as well as the momentum-dependent localization of the arcs. Motivated by the experimentally observed recovery of inversion symmetry under pressure or upon doping, we interpolate between the two structures and determine the energy and momentum dependence of the Weyl nodes. For deeper insights into the surface superconductivity of PtBi$_2$, we construct a symmetry-adapted effective four-band model that accurately reproduces the Weyl points of PtBi$_2$. We supplement this model with an analysis of the symmetry-allowed pairings between the Fermi arcs, which naturally mix spin-singlet and spin-triplet channels. Moreover, the presence of surface-only superconductivity facilitates an intrinsic superconductor-semimetal-superconductor Josephson junction, with the semimetallic phase sandwiched between the two superconducting surfaces. For a phase difference of $π$, zero-energy Andreev bound states develop between the two terminations.
title Electronic structure of the surface superconducting Weyl semimetal PtBi$_2$
topic Superconductivity
Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2404.19606