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Ferroelectric Surface Potentials Enable Band-Alignment Engineering for Tunable Quantum Anomalous Hall States.
Shuhan Shan1, Yan Liang1,2, Pei Zhao1,2
1College of Physics and Optoelectronic Engineering, Ocean University of China, Qingdao 266100, People's Republic of China.
Nano Letters
|May 23, 2026
Summary
Ferroelectric substrates enable tunable band alignment in quantum anomalous Hall (QAH) heterostructures. This control switches between metallic and QAH insulating states, paving the way for novel electronic devices.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Phenomena
Background:
- Quantum anomalous Hall (QAH) effect requires specific band alignment in heterostructures to maintain topological gaps.
- Band alignment in 2D heterostructures is usually fixed by material choice, limiting tunability.
Purpose of the Study:
- To demonstrate a nonvolatile method for engineering band alignment in QAH heterostructures.
- To explore the use of ferroelectric substrates for controlling topological phase transitions.
Main Methods:
- Utilized first-principles calculations to model a fluorinated MoSe2 monolayer on an In2S3 ferroelectric substrate.
- Investigated the impact of ferroelectric polarization on surface electrostatic potential and band alignment.
Main Results:
- Ferroelectric polarization generates a surface potential that shifts energy levels in adjacent layers.
- Demonstrated a switchable band alignment from type-III to type-I through polarization reversal.
- Achieved controllable topological phase transitions from metallic to QAH insulating states.
Conclusions:
- Ferroelectric substrates offer a novel, nonvolatile route to actively engineer band alignment in 2D heterostructures.
- This tunability enables the control of topological phase transitions, crucial for QAH effect applications.
Keywords:
Band alignment engineeringFerroelectricityFirst-principles calculationsQuantum anomalous Hall effectvan der Waals heterostructuresMore Related Videos
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