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In-Plane Field Induced Half Quantized Hall Conductivity in Trilayer Magnetic Topological Insulator.
Ting-Hsun Yang1, Yaochen Li1, Peng Zhang1
1Department of Electrical and Computer Engineering, University of California, Los Angeles, CA, 90095, USA.
Advanced Materials (Deerfield Beach, Fla.)
|November 25, 2025
Summary
Researchers achieved half-quantized Hall conductivity (hQHC) in magnetic topological insulators. This breakthrough offers a new pathway to study the parity anomaly and design quantum devices.
Area of Science:
- Condensed Matter Physics
- High-Energy Physics
- Materials Science
Background:
- The parity anomaly, originating in high-energy physics, is observed in condensed matter systems exhibiting a single Dirac cone.
- A key signature is half-quantized Hall conductivity (hQHC).
Purpose of the Study:
- To establish a novel method for achieving hQHC in trilayer magnetic topological insulators.
- To investigate the manipulation of the topological magnetoelectric effect.
Main Methods:
- Utilized trilayer magnetic topological insulators with distinct magnetic dopants on top and bottom surfaces.
- Employed in-plane magnetic fields and angle-resolved magneto-transport measurements.
- Tuned interlayer exchange coupling via non-magnetic spacer thickness.
Main Results:
- Successfully achieved hQHC in the engineered trilayer system.
- Characterized differing perpendicular magnetic anisotropy energies of surface magnetism.
- Gained insights into controlling the topological magnetoelectric effect through field orientation.
Conclusions:
- Demonstrated a new route to hQHC, enabling the study of the parity anomaly.
- The findings provide a technical pathway for stabilizing single Dirac cones with hQHC.
- Paves the way for designing advanced topological quantum devices.
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