Continuum Landau surface states in a non-Hermitian Weyl semimetal

Abstract

The surface states of certain topological phases can be linked to a quantum anomaly: the violation of a classical symmetry by a field theory via a non-conserved current. This has been generalized to the case of a non-Hermitian (NH) chiral anomaly affecting the surfaces states of an NH Weyl phase. Here, we show that the NH anomaly inflow is mediated by continnum Landau modes (CLMs): special eigenstates exhibiting both spatial localization and a continuous spectrum, contrary to the usual distinction between bound and free states. The number of anomaly-induced surface modes scales with the sample volume rather than its surface area, which is shown to be tied to the unusual multiplicity of the CLMs. The other properties of the CLMs, including their normalization conditions and localization scale, closely match the predictions of the NH field theory. Finally, we discuss the conditions under which these phenomena can be probed experimentally using metamaterials.

arXiv comment10 pages, 5 figures

References in corpus (39)

• Weyl and Dirac Semimetals in Three Dimensional Solids
• Topological Field Theory of Time-Reversal Invariant Insulators
• Making Sense of Non-Hermitian Hamiltonians
• Classification of topological quantum matter with symmetries
• The Chiral Magnetic Effect
• Unidirectional Invisibility induced by PT-Symmetric Periodic Structures
• Exceptional Topology of Non-Hermitian Systems
• Localization transitions in non-Hermitian quantum mechanics
• Topological phases of non-Hermitian systems
• Symmetry and Topology in Non-Hermitian Physics
• Topological Band Theory for Non-Hermitian Hamiltonians
• Anomalous edge state in a non-Hermitian lattice
• Topological response in Weyl semimetals and the chiral anomaly
• Observation of bulk boundary correspondence breakdown in topolectrical circuits
• Efficient Light Funneling based on the non-Hermitian Skin Effect
• Edge Modes, Degeneracies, and Topological Numbers in Non-Hermitian Systems
• Quantization of fractional corner charge in $C_n$-symmetric higher-order topological crystalline insulators
• Quantum Oscillations from Surface Fermi-Arcs in Weyl and Dirac Semi-Metals
• Classical higher-order topological insulators
• Topological acoustics
• Universal non-Hermitian skin effect in two and higher dimensions
• Non-Hermitian Morphing of Topological Modes
• A fractional corner anomaly reveals higher-order topology
• Exponentially-enhanced quantum sensing with non-Hermitian lattice dynamics
• Observation of Weyl point pair annihilation in a gyromagnetic photonic crystal
• Exceptional Topological Insulators
• Topological Field Theory of Non-Hermitian Systems
• Geometric Response and Disclination-Induced Skin Effects in Non-Hermitian Systems
• Quantum oscillations from generic surface Fermi arcs and bulk chiral modes in Weyl semimetals
• Anomalous Floquet non-Hermitian skin effect in a ring resonator lattice
• Symmetries and conservation laws in non-Hermitian field theories
• Non-Hermitian Topological Phases: Principles and Prospects
• Non-Hermitian Photonic Lattices: tutorial
• Optomechanical realization of the bosonic Kitaev-Majorana chain
• Bulk-boundary correspondence in point-gap topological phases
• Quantum Simulation of the Bosonic Kitaev Chain
• Continuum of Bound States in a Non-Hermitian Model
• Non-Hermitian spatial symmetries and their stabilized normal and exceptional topological semimetals
• Signature of Parity Anomaly: Crossover from One Half to Integer Quantized Hall Conductance in a Finite Magnetic Field