Fractional Electromagnetic Response in Three-Dimensional Chiral Anomalous Semimetal

Abstract

The magnetoelectric coupling of electrons in a three-dimensional solid can be effectively described by axion electrodynamics. Here we report the discovery of the fractional magnetoelectric effect in chiral anomalous semimetals of the three-dimensional massless Wilson fermions, which have linear dispersions at the energy crossing point, and break the chiral symmetry at generic momenta. In the presence of electric and magnetic fields, the time-reversal and parity symmetry breaking give rise to the quarter-quantized topological magnetoelectric effect, which is directly related to the winding number 1/2 of the band structure, and is only one half of that for topological insulators. The fractional electromagnetic response can be revealed by the surface Hall conductance and extracted from the measurement of the topological Kerr and Faraday rotation. The transition-metal pentatelluride \mathrm{ZrTe_{5}} with a strain-tunable band gap provides a potential platform to test the effect experimentally.

11 pages, 3 figures

References in corpus (7)

• Classification of topological insulators and superconductors in three spatial dimensions
• Topological Field Theory of Time-Reversal Invariant Insulators
• Observation and control of the weak topological insulator state in ZrTe5
• Resonant spin Hall conductance in quantum Hall systems lacking bulk and structural inversion symmetry
• Half-Quantized Hall Effect and Power Law Decay of Edge Current Distribution
• The Bulk-Hinge Correspondence and Three-Dimensional Quantum Anomalous Hall Effect in Second Order Topological Insulators
• Helical Symmetry Breaking and Quantum Anomaly in Massive Dirac Fermions

Cited by in corpus (4)

• Observation of the dual quantum spin Hall insulator by density-tuned correlations in a van der Waals monolayer
• Calculations of Chern number: equivalence of real-space and twisted-boundary-condition formulae
• Dirac Fermions and Topological Phases in Magnetic Topological Insulator Films
• The One-dimensional Chiral Anomaly and its Disorder Response