Half-Quantized Hall Effect at the Parity-Invariant Fermi Surface

Abstract

Condensed matter realization of a single Dirac cone of fermions in two dimensions is a long-standing issue. Here we report the discovery of a single gapless Dirac cone of half-quantized Hall conductance in a magnetically-doped topological insulator heterostructure. It demonstrates that the Hall conductance is half-quantized in the unit e^{2}/h when the parity symmetry is invariant near the Fermi surface. The gapless Dirac point is stable and protected by the local parity symmetry and the topologically nontrivial band structure of the topological insulator. The one-half Hall conductance observed in a recent experiment [Mogi et al, Nat. Phys. 18, 390 (2022)] is attributed to the existence of the gapless Dirac cone. The results suggest a condensed matter realization of a topological phase with a one-half topological invariant.

6 pages with 4 figures

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Cited by in corpus (15)

• Light-induced half-quantized Hall effect and axion insulator
• Altermagnetism-Induced Parity Anomaly in Weak Topological Insulators
• Signature of Parity Anomaly: Crossover from One Half to Integer Quantized Hall Conductance in a Finite Magnetic Field
• Quantum Anomalous Hall Effect in Ferromagnetic Metals
• Calculations of Chern number: equivalence of real-space and twisted-boundary-condition formulae
• On the half-quantized Hall conductance of massive surface electrons in magnetic topological insulator films
• Metallic Quantized Anomalous Hall Effect without Chiral Edge States
• Dirac Fermions and Topological Phases in Magnetic Topological Insulator Films
• Ferroelectrically Switchable Half-Quantized Hall Effect
• Anomalous Coherence Length of Majorana Zero Modes at Vortices in Superconducting Topological Insulators
• The One-dimensional Chiral Anomaly and its Disorder Response
• Half-Quantized Hall Metal and Marginal Metal in Disordered Magnetic Topological Insulators
• Parity Anomalous Semimetal with Minimal Conductivity Induced by an In-Plane Magnetic Field
• Absence of Parity Anomaly in Massive Dirac Fermions on a Lattice
• Disordered Parity Anomalous Semimetal