Disorder-induced exceptional points and nodal lines in Dirac superconductors

Abstract

We consider the effect of disorder on the spectrum of quasiparticles in the point-node and nodal-line superconductors. Due to the anisotropic dispersion of quasiparticles disorder scattering may render the Hamiltonian describing these excitations non-Hermitian. Depending on the dimensionality of the system, we show that the nodes in the spectrum are replaced by Fermi arcs or Fermi areas bounded by exceptional points or exceptional lines, respectively. These features are illustrated by first considering a model of a proximity-induced superconductor in an anisotropic two-dimensional (2D) Dirac semimetal, where a Fermi arc in the gap bounded by exceptional points can be realized. We next show that the interplay between disorder and supercurrents can give rise to a 2D Fermi surface bounded by exceptional lines in three-dimensional (3D) nodal superconductors.

10 pages, 5 figures

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Cited by in corpus (6)

• Braiding of Majorana corner states in electric circuits and its non-Hermitian generalization
• Non-Hermitian Boundary in a Surface Selective Reconstructed Magnetic Weyl Semimetal
• Non-Hermitian Josephson junctions with four Majorana zero modes
• Topological spin textures in electronic non-Hermitian systems
• Disorder-driven exceptional points and concurrent topological phase transitions in non-Hermitian systems
• Floquet spin textures in optically pumped non-Hermitian surface states