Higher-order topological superconductors in ${\mathcal P}$-, ${\mathcal T}$-odd quadrupolar Dirac materials

Bitan Roy

doi:10.1103/PhysRevB.101.220506

paper

Higher-order topological superconductors in $P$ -, $T$ -odd quadrupolar Dirac materials

arXiv:2003.12566 · doi:10.1103/PhysRevB.101.220506

Abstract

The presence or absence of certain symmetries in the normal state (NS) also determines the symmetry of the Cooper pairs. Here we show that parity ( $P$ ) and time-reversal ( $T$ ) odd Dirac insulators (trivial or topological) or metals, sustain a local or intra-unit cell pairing that supports corner (in $d = 2$ ) or hinge (in $d = 3$ ) modes of Majorana fermions and stands as a higher-order topological superconductor (HOTSC), when the NS additionally breaks discrete four-fold ( $C_{4}$ ) symmetry. Although these outcomes does not rely on the existence of a Fermi surface, around it (when the system is doped) the HOTSC takes the form of a mixed parity, $T$ -odd (due to the lack of $P$ and $T$ in the NS, respectively) $p + i d$ pairing, where the $p$ ( $d$ )-wave component stems from the Dirac nature of quasiparticles (lack of $C_{4}$ symmetry) in the NS. Thus, when strained, magnetically ordered Dirac materials, such as doped magnetic topological insulators (MnBi $_{2}$ Te $_{4}$ ), can harbor HOTSCs, while the absence of an external strain should be conducive for the axionic $p + i s$ pairing.

arXiv comment5 Pages, 3 Figures, 2 Tables: Published version

Higher-order topological superconductors in $P$ -, $T$ -odd quadrupolar Dirac materials

Abstract

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Cited by in corpus (58)

Higher-order topological superconductors in P-, T-odd quadrupolar Dirac materials

Abstract

References in corpus (39)

Cited by in corpus (58)

Higher-order topological superconductors in $P$ -, $T$ -odd quadrupolar Dirac materials