SciPost Physics

SciPost Phys. 12, 053 (2022) · published 4 February 2022

• doi: 10.21468/SciPostPhys.12.2.053
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Abstract

We propose that doped Weyl semimetals with {time-reversal and certain crystalline symmetries} are natural candidates to realize higher-order topological superconductors, which exhibit a fully gapped bulk while the surface hosts robust gapless chiral hinge states. We show that in such a doped Weyl semimetal, a featureless finite-range attractive interaction favors a $p+ip$ pairing symmetry. By analyzing its topological properties, we identify such a chiral pairing state as a higher-order topological superconductor, which depending on the existence of a four-fold rotoinversion symmetry, is either intrinsic, {meaning that the corresponding hinge states can only be removed by closing the bulk gap, rather than modifying the surface states}, or extrinsic. We achieve this understanding via various methods recently developed for higher-order topology, including Wannier representability, Wannier spectrum, and defect classification approaches. For the four-fold rotoinversion symmetric case, we provide a complete classification of the higher-order topological superconductors. We show that such second-order topological superconductors exhibit chiral hinge modes that are robust in the absence of interaction effects but can be eliminated at the cost of introducing surface topological order.

• Vasiloiu et al., Dephasing-enhanced Majorana zero modes in two-dimensional and three-dimensional higher-order topological superconductors
  Phys. Rev. B 106, L060307 (2022) [Crossref]
• Lin et al., Two-dimensional-like superconducting properties and weak antilocalization transport in FeSe0.4Te0.6 single crystals: Topology-driven magnetotransport
  Phys. Rev. B 108, 214509 (2023) [Crossref]
• Ghosh et al., Hinge-mode dynamics of periodically driven higher-order Weyl semimetals
  Phys. Rev. B 105, 224312 (2022) [Crossref]
• Zhu et al., Sublattice-sensitive Majorana modes
  Phys. Rev. B 106, 245418 (2022) [Crossref]
• Wu et al., Nodal higher-order topological superconductivity from a C4 -symmetric Dirac semimetal
  Phys. Rev. B 106, 214510 (2022) [Crossref]
• Jahin et al., Higher-order topological superconductivity in monolayer WTe2 from repulsive interactions
  Phys. Rev. B 108, 014509 (2023) [Crossref]
• Huang et al., Hybrid-order topological superconductivity in a topological metal 1T’-MoTe2
  npj Quantum Mater. 9, 21 (2024) [Crossref]
• Scammell et al., Intrinsic first- and higher-order topological superconductivity in a doped topological insulator
  Phys. Rev. B 105, 195149 (2022) [Crossref]
• Li et al., Anomalous gapped boundaries between surface topological orders in higher-order topological insulators and superconductors with inversion symmetry
  Phys. Rev. B 106, 125121 (2022) [Crossref]
• Kheirkhah et al., Corner- and sublattice-sensitive Majorana zero modes on the kagome lattice
  Phys. Rev. B 106, 085420 (2022) [Crossref]
• Wang et al., Edge and corner superconductivity in a two-dimensional topological model
  Phys. Rev. B 107, 104507 (2023) [Crossref]