Topological superconductivity enhanced by exceptional points

Abstract

Majorana zero modes (MZMs) emerge as edge states in topological superconductors and are promising for topological quantum computation, but their detection has so far been elusive. Here we show that non-Hermiticity can be used to obtain dramatically more robust MZMs. The enhanced properties appear as a result of an extreme instability of exceptional points to superconductivity, such that even a vanishingly small superconducting order parameter already opens a large energy gap, produces well-localized MZMs, and leads to strong superconducting pair correlations. Our work thus illustrates the large potential of enhancing topological superconductivity using non-Hermitian exceptional points.

7+15 pages, 4+7 figures. Supplementary videos available at https://github.com/rarouca/Hatano-Nelson-Kitaev/ v2: addition of analytic calculations close to the EP and of background in non-Hermitian systems. Title changed following editor suggestion

References in corpus (29)

• Signatures of Majorana fermions in hybrid superconductor-semiconductor nanowire devices
• Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
• Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
• The physics of exceptional points
• Topological Origin of Non-Hermitian Skin Effects
• Superconductivity in rhombohedral trilayer graphene
• Isospin magnetism and spin-triplet superconductivity in Bernal bilayer graphene
• New topological invariants in non-Hermitian systems
• Symmetry and Higher-Order Exceptional Points
• Symmetry-protected multifold exceptional points and their topological characterization
• The transfer matrix: a geometrical perspective
• Majorana bound states and non-local spin correlations in a quantum wire on an unconventional superconductor
• Majorana splitting from critical currents in Josephson junctions
• Majorana modes and $p$-wave superfluids for fermionic atoms in optical lattices
• Realizing exceptional points of any order in the presence of symmetry
• Fate of Majorana zero modes, critical states and non-conventional real-complex transition in non-Hermitian quasiperiodic lattices
• In search of Majorana
• Classification of Exceptional Nodal Topologies Protected by $\mathcal{P}\mathcal{T}$ Symmetry
• Exceptional odd-frequency pairing in non-Hermitian superconducting systems
• Defective Majorana zero modes in non-Hermitian Kitaev chain
• Response strengths of open systems at exceptional points
• Signatures of Topological Superconductivity in Bulk Insulating Topological Insulator BiSbTe${}_{1.25}$Se${}_{1.75}$ in Proximity with Superconducting NbSe${}_2$
• Non-Hermitian dynamics and $\mathcal{P}\mathcal{T}$-symmetry breaking in interacting mesoscopic Rydberg platforms
• Degeneracy and defectiveness in non-Hermitian systems with open boundary
• Probing non-Hermitian phase transitions in curved space via quench dynamics
• Symmetry protected exceptional points of interacting fermions
• Exact formulas of the end-to-end Green's functions in non-Hermitian systems
• Universal characteristics of one-dimensional non-Hermitian superconductors
• Non-Hermitian quantum gases: a platform for imaginary time crystals

Cited by in corpus (12)

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• Non-Hermitian phase-biased Josephson junctions
• Non-hermitian topology in multiterminal superconducting junctions
• Entanglement transitions in a periodically driven non-Hermitian Ising chain
• Andreev non-Hermitian Hamiltonian for open Josephson junctions from Green's functions
• Hilbert space fragmentation imposed real spectrum of non-Hermitian systems
• Light-induced Floquet spin-triplet Cooper pairs in unconventional magnets
• Majorana zero-modes in a dissipative Rashba nanowire
• Braids and Higher-order Exceptional Points from the Interplay Between Lossy Defects and Topological Boundary States
• Non-Hermitian skin effect and electronic nonlocal transport
• Supercurrent from the imaginary part of the Andreev levels in non-Hermitian Josephson junctions
• Dissipation-Induced Steady States in Topological Superconductors: Mechanisms and Design Principles