Exceptional degeneracies in non-Hermitian Rashba semiconductors

Abstract

Exceptional points are spectral degeneracies of non-Hermitian systems where eigenvalues and eigenvectors coalesce, inducing unique topological phases that have no counterpart in the Hermitian realm. Here we consider a non-Hermitian system by coupling a two-dimensional semiconductor with Rashba spin-orbit coupling to a ferromagnet lead and show the emergence of highly tunable exceptional points along rings in momentum space. Interestingly, these exceptional degeneracies are the endpoints of lines formed by the eigenvalue coalescence at finite real energy, resembling the bulk Fermi arcs commonly defined at zero real energy. We then show that an in-plane Zeeman field provides a way to control these exceptional degeneracies although higher values of non-Hermiticity are required in contrast to the zero Zeeman field regime. Furthermore, we find that the spin projections also coalescence at the exceptional degeneracies and can acquire larger values than in the Hermitian regime. Finally, we demonstrate that the exceptional degeneracies induce large spectral weights, which can be used as a signature for their detection. Our results thus reveal the potential of systems with Rashba spin-orbit coupling for realizing non-Hermitian bulk phenomena.

arXiv comment10 pages, 5 figures. Published version

References in corpus (61)

• New Perspectives for Rashba Spin-Orbit Coupling
• Exceptional Topology of Non-Hermitian Systems
• Non-Hermitian Physics
• Topological phases of non-Hermitian systems
• The physics of exceptional points
• Symmetry and Topology in Non-Hermitian Physics
• Dynamically encircling exceptional points in a waveguide: asymmetric mode switching from the breakdown of adiabaticity
• Realizing Majorana zero modes in superconductor-semiconductor heterostructures
• Observation of Bulk Fermi Arc and Polarization Half Charge from Paired Exceptional Points
• Observation of non-Hermitian degeneracies in a chaotic exciton-polariton billiard
• Non-Hermitian Topology and Exceptional-Point Geometries
• Electronic structure of quantum materials studied by angle-resolved photoemission spectroscopy
• From Andreev to Majorana bound states in hybrid superconductor-semiconductor nanowires
• Periodic Table for Topological Bands with Non-Hermitian Bernard-LeClair Symmetries
• Classification of Exceptional Points and Non-Hermitian Topological Semimetals
• Evidence of topological superconductivity in planar Josephson junctions
• Two-dimensional epitaxial superconductor-semiconductor heterostructures: A platform for topological superconducting networks
• Observation of an exceptional point in a chaotic optical microcavity
• Angle-resolved photoemission spectroscopy and its application to topological materials
• Non-Hermitian perspective of the band structure in heavy-fermion systems
• Exceptional rings in two-dimensional correlated systems with chiral symmetry
• Majorana bound states from exceptional points in non-topological superconductors
• Zero-Energy Modes from Coalescing Andreev States in a Two-Dimensional Semiconductor-Superconductor Hybrid Platform
• Theory of Non-Hermitian Fermionic Superfluidity with a Complex-Valued Interaction
• Topological exceptional surfaces in non-Hermitian systems with parity-time and parity-particle-hole symmetries
• Symmetry and Higher-Order Exceptional Points
• Quantized conductance doubling and hard gap in a two-dimensional semiconductor-superconductor heterostructure
• SNS junctions in nanowires with spin-orbit coupling: role of confinement and helicity on the sub-gap spectrum
• Symmetry-protected multifold exceptional points and their topological characterization
• Non-Hermitian topology: a unifying framework for the Andreev versus Majorana states controversy
• Hall Conductance of a Non-Hermitian Chern Insulator
• Non-Hermitian Topological Theory of Finite-Lifetime Quasiparticles: Prediction of Bulk Fermi Arc Due to Exceptional Point
• Zero-field Topological Superconductivity in Ferromagnetic Hybrid Nanowires
• Non-Hermitian Weyl Physics in Topological Insulator Ferromagnet Junctions
• Conductance through a helical state in an InSb nanowire
• Superconducting, Insulating, and Anomalous Metallic Regimes in a Gated Two-Dimensional Semiconductor-Superconductor Array
• DMFT reveals the non-Hermitian topology in heavy-fermion systems
• Engineering Hybrid Epitaxial InAsSb/Al Nanowire Materials for Stronger Topological Protection
• Semiconductor - Ferromagnetic Insulator - Superconductor Nanowires: Stray Field and Exchange Field
• Theory of superconductivity with non-Hermitian and parity-time reversal symmetric cooper pairing symmetry
• Ballistic superconductivity and tunable $\pi$-junctions in InSb quantum wells
• Knot topology of exceptional point and non-Hermitian no-go theorem
• Loss of Hall Conductivity Quantization in a Non-Hermitian Quantum Anomalous Hall Insulator
• Topological properties of superconducting junctions
• Low-Temperature and High-Energy-Resolution Laser Photoemission Spectroscopy
• Two types of topological transitions in finite Majorana wires
• Exceptional band touching for strongly correlated systems in equilibrium
• Exceptional odd-frequency pairing in non-Hermitian superconducting systems
• Spin transport in ferromagnet-InSb nanowire quantum devices
• Exceptional points in the one-dimensional Hubbard model
• Evidence for spin-polarized bound states in semiconductor-superconductor-ferromagnetic insulator islands
• Supercurrent reversal in ferromagnetic hybrid nanowire Josephson junctions
• Epitaxial Superconductor-Semiconductor Two-Dimensional Systems for Superconducting Quantum Circuits
• Strong and tunable spin-orbit interaction in a single crystalline InSb nanosheet
• Quantum transport in high-quality shallow InSb quantum wells
• Semiconductor-ferromagnet-superconductor planar heterostructures for 1D topological superconductivity
• Bulk Bogoliubov Fermi arcs in non-Hermitian superconducting systems
• Signature of PT-symmetric non-Hermitian superconductivity in angle-resolved photoelectron fluctuation spectroscopy
• Gate defined quantum dot realized in a single crystalline InSb nanosheet
• Tunneling conductance in two-dimensional junctions between a normal metal and a ferromagnetic Rashba metal
• Unconventional gate voltage dependence of the charge conductance caused by spin-splitting Fermi surface by Rashba-type spin-orbit coupling

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