Non-Hermitian Boundary in a Surface Selective Reconstructed Magnetic Weyl Semimetal
arXiv:2402.14518 · doi:10.1002/adma.202419559
Abstract
Non-Hermitian physics, studying systems described by non-Hermitian Hamiltonians, reveals unique phenomena not present in Hermitian systems. Unlike Hermitian systems, non-Hermitian systems have complex eigenvalues, making their effects less directly observable. Recently, significant efforts have been devoted to incorporating the non-Hermitian effects into condensed matter physics. However, progress has been hindered by the absence of a viable experimental approach. Here, the discovery of surface-selectively spontaneous reconstructed Weyl semimetal NdAlSi provides a feasible experimental platform for studying non-Hermitian physics. Utilizing angle-resolved photoemission spectroscopy measurements, surface-projected density functional theory calculations, and scanning tunneling microscopy measurements, we demonstrate that surface reconstruction in NdAlSi alters surface Fermi arc connectivity and generates new isolated non-topological surface Fermi arcs. In the presence of a magnetic field, the surface-selective spontaneous reconstructed Weyl semimetal NdAlSi can be viewed as a Hermitian bulk--non-Hermitian boundary system. The isolated non-topological surface Fermi arcs on the reconstructed surface act as a loss mechanism and open boundary condition for the topological electrons and bulk states, serving as non-Hermitian boundary states. This discovery provides a good experimental platform for exploring new physical phenomena and potential applications based on boundary non-Hermitian effects, extending beyond purely mathematical concepts.
21 pages, 4 figures
References in corpus (42)
- Quantum ESPRESSO: a modular and open-source software project for quantum simulations of materials
- Phonons and related properties of extended systems from density-functional perturbation theory
- Making Sense of Non-Hermitian Hamiltonians
- Edge states and topological invariants of non-Hermitian systems
- Exceptional Topology of Non-Hermitian Systems
- Non-Hermitian Physics
- Localization transitions in non-Hermitian quantum mechanics
- Topological Origin of Non-Hermitian Skin Effects
- Destruction of the Fermi Surface in Underdoped High Tc Superconductors
- Observation of bulk boundary correspondence breakdown in topolectrical circuits
- Spawning rings of exceptional points out of Dirac cones
- Observation of Bulk Fermi Arc and Polarization Half Charge from Paired Exceptional Points
- Non-Hermitian Topology and Exceptional-Point Geometries
- Non-Hermitian bulk-boundary correspondence and auxiliary generalized Brillouin zone theory
- Pump-induced Exceptional Points in Lasers
- Critical non-Hermitian Skin Effect
- Non-Hermitian topological phenomena: A review
- Observation of hybrid higher-order skin-topological effect in non-Hermitian topolectrical circuits
- Non-Hermitian skin modes induced by on-site dissipations and chiral tunneling effect
- Topological Non-Hermitian skin effect
- Observation of an exceptional point in a chaotic optical microcavity
- Non-Hermitian perspective of the band structure in heavy-fermion systems
- Exceptional rings in two-dimensional correlated systems with chiral symmetry
- Bulk-edge correspondence for two-dimensional topological insulators
- Flat Band in Disorder Driven Non-Hermitian Weyl Semimetals
- Nodal Arc in Disordered Dirac Fermions: Connection to Non-Hermitian Band Theory
- Jones polynomial and knot transitions in topological semimetals
- Non-Hermitian Weyl Physics in Topological Insulator Ferromagnet Junctions
- Disorder-driven exceptional lines and Fermi ribbons in tilted nodal-line semimetals
- Observation of Weyl fermions in a magnetic non-centrosymmetric crystal
- Controlled topological phases and bulk-edge correspondence
- Loss of Hall Conductivity Quantization in a Non-Hermitian Quantum Anomalous Hall Insulator
- Emergence of Fermi arcs and novel magnetic splitting in an antiferromagnet
- Hermitian Bulk -- Non-Hermitian Boundary Correspondence
- Disorder-induced exceptional points and nodal lines in Dirac superconductors
- First-principles study on the double-dome superconductivities in kagome material CsVSb under pressure
- Ferrimagnetic Regulation of Weyl Fermions in a Noncentrosymmetric Magnetic Weyl Semimetal
- Observation of Fermi arcs and Weyl nodes in a non-centrosymmetric magnetic Weyl semimetal
- Kramers nodal lines and Weyl fermions in SmAlSi
- Stripe Helical Magnetism and Two Regimes of Anomalous Hall Effect in NdAlGe
- Signature of weakly coupled electrons and conduction electrons in magnetic Weyl semimetal candidates PrAlSi and SmAlSi
- Unusual Electronic Structure of Dirac Material BaMnSb Revealed by Angle-Resolved Photoemission Spectroscopy