Symmetry-protected topological invariant and Majorana impurity states in time-reversal-invariant superconductors

Abstract

We address the question of whether individual nonmagnetic impurities can induce zero-energy states in time-reversal-invariant topological superconductors, and define a class of symmetries which guarantee the existence of such states for a specific value of the impurity strength. These symmetries allow the definition of a position-space topological Z_2 invariant, which is related to the standard bulk topological Z_2 invariant. Our general results are applied to the time-reversal-invariant p-wave phase of the doped Kitaev-Heisenberg model, where we demonstrate how a lattice of impurities can drive a topologically trivial system into the nontrivial phase.

published version

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Cited by in corpus (9)

• Destabilization of magnetic order in a dilute Kitaev spin liquid candidate
• Existence of zero-energy impurity states in different classes of topological insulators and superconductors and their relation to topological phase transitions
• Anderson Topological Superconductor
• Topological superconductivity in the extended Kitaev-Heisenberg model
• Impact of topology on the impurity effects in extended $s$-wave superconductors with spin-orbit coupling
• Hydrated lithium intercalation into the Kitaev spin liquid candidate material $\alpha -$RuCl${}_3$
• Tunable topological states hosted by unconventional superconductors with adatoms
• Symmetry analysis of transport properties in helical superconductor junctions
• Effects of electron-electron interactions in the Yu-Shiba-Rusinov lattice model