Half-Quantized Hall Metal and Marginal Metal in Disordered Magnetic Topological Insulators
arXiv:2508.19534 · doi:10.1038/s42005-025-02252-5
Abstract
A semimagnetic topological insulator -- a heterostructure combining a topological insulator with a ferromagnet -- exhibits a half-quantized Hall effect, characterized by a quantized Hall conductance of (where is the elementary charge and is the Planck constant), which reinforces the established understanding of topological phenomena in condensed matter physics. However, its stability in realistic, disordered systems remains poorly understood. Here, we demonstrate the robustness of the half-quantized Hall effect in weakly disordered systems, stemming from a single gapless Dirac cone of fermions and coexisting with weak antilocalization due to the Berry phase that suppresses backscattering. Furthermore, we uncover a marginal metallic phase emerging between weak antilocalization and Anderson insulation -- a transition that defies conventional metal-insulator transitions by lacking an isolated critical point -- where both conductance and normalized localization length exhibit scale invariance, independent of system size. The half-quantized Hall metal and the marginal metallic phase challenge existing localization theories and provide insights into disorder-driven topological phase transitions in magnetic topological insulators, opening avenues for exploring quantum materials and next-generation electronic devices.
arXiv comment29 pages, 6 figures
References in corpus (58)
- Topological insulators and superconductors
- Berry Phase Effects on Electronic Properties
- Anomalous Hall effect
- Experimental Observation of the Quantum Anomalous Hall Effect in a Magnetic Topological Insulator
- Quantized Anomalous Hall Effect in Magnetic Topological Insulators
- Anderson Transitions
- The Kernel Polynomial Method
- Scaling Theory of the Integer Quantum Hall Effect
- Berry Curvature on the Fermi Surface: Anomalous Hall Effect as a Topological Fermi-Liquid Property
- Signatures of Fractional Quantum Anomalous Hall States in Twisted MoTe2 Bilayer
- Observation of Fractionally Quantized Anomalous Hall Effect
- Trajectory of Anomalous Hall Effect toward the Quantized State in a Ferromagnetic Topological Insulator
- Massive Dirac fermions and spin physics in an ultrathin film of topological insulator
- Colloquium: Quantum anomalous Hall effect
- Theory of the topological Anderson insulator
- Demonstration of one-parameter scaling at the Dirac point in graphene
- Competition between weak localization and antilocalization in topological surface states
- Topological delocalization of two-dimensional massless Dirac fermions
- Topological Anderson Insulator in Three Dimensions
- Localization and Kosterlitz-Thouless Transition in Disordered Graphene
- Quantum criticality and minimal conductivity in graphene with long-range disorder
- Disorder and metal-insulator transitions in Weyl semimetals
- Disordered Topological Insulators: A Non-Commutative Geometry Perspective
- Topological Phase Transitions in Disordered Electric Quadrupole Insulators
- The Anderson Transition in Two-Dimensional Systems with Spin-Orbit Coupling
- Anderson localization and the quantum phase diagram of three dimensional disordered Dirac semimetals
- Hall Conductance of a Non-Hermitian Chern Insulator
- Disordered weak and strong topological insulators
- Surface-edge state and half quantized Hall conductance in topological insulators
- Linear Scaling Quantum Transport Methodologies
- Localization and Mobility Gap in Topological Anderson Insulator
- Effective Field Theory of Electron Motion in the Presence of Random Magnetic Flux
- Numerical estimation of the -function in 2D systems with spin-orbit coupling
- Metal-insulator transition in 2D random fermion systems of chiral symmetry classes
- Half-Quantized Hall Effect and Power Law Decay of Edge Current Distribution
- Critical regime of two dimensional Ando model: relation between critical conductance and fractal dimension of electronic eigenstates
- Critical Exponent of the Anderson Transition using Massively Parallel Supercomputing
- Disorder-induced Majorana zero modes in a dimerized Kitaev superconductor chain
- Criticality of the metal-topological insulator transition driven by disorder
- Effects of random domains on the zero Hall plateau in quantum anomalous Hall effect
- Half-Quantized Hall Effect at the Parity-Invariant Fermi Surface
- Disorder-Induced Quantum Phase Transitions in Three-Dimensional Second-Order Topological Insulators
- Topological Anderson insulator phase in a Dirac-semimetal thin film
- Critical Metal Phase at the Anderson Metal-Insulator Transition with Kondo Impurities
- Emergence of integer quantum Hall effect from chaos
- Algebraic and Geometric Mean Density of States in Topological Anderson Insulators
- Half-Quantized Helical Hinge Currents in Axion Insulators
- Phase diagrams of Weyl semimetals with competing intraorbital and interorbital disorders
- Anisotropic Topological Anderson Transitions in Chiral Symmetry Classes
- Extrinsic anomalous Hall conductivity of a topologically nontrivial conduction band
- Unusual Metal to Marginal-Metal Transition in Two-Dimensional Ferromagnetic Electron Gases
- Signature of Parity Anomaly: Crossover from One Half to Integer Quantized Hall Conductance in a Finite Magnetic Field
- Metal-insulator transition in a 2D system of chiral unitary class
- Weak quantization of non-interacting topological Anderson insulator
- Quarter-quantized thermal Hall effect with parity anomaly
- Topological effect on the Anderson transition in chiral symmetry classes
- Anderson Critical Metal Phase in Trivial States Protected by Average Magnetic Crystalline Symmetry
- Chiral Surface Modes in Three-Dimensional Topological Insulators