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High-temperature quantum valley Hall effect with quantized resistance and a topological switch.
Ke Huang1, Hailong Fu1, Kenji Watanabe2
1Department of Physics, The Pennsylvania State University, University Park, PA 16802, USA.
Science (New York, N.Y.)
|July 18, 2024
Summary
Researchers observed robust quantized resistance plateaus in kink states of topological insulators, paving the way for novel electron quantum optics devices. This breakthrough addresses challenges in conductance quantization for helical edge states.
Area of Science:
- Condensed matter physics
- Quantum mechanics
- Materials science
Background:
- Topological insulators exhibit unique edge states crucial for exploring low-dimensionality and topology.
- Achieving robust conductance quantization in helical edge states remains a significant challenge.
Purpose of the Study:
- To investigate the properties of kink states in Bernal bilayer graphene.
- To demonstrate the potential of these states for practical electronic devices.
Main Methods:
- Experimental observation of resistance plateaus in kink states.
- Characterization of plateau resistance dependence on temperature and DC bias.
- Demonstration of a topology-controlled switch.
Main Results:
- Observed wide resistance plateaus in kink states, quantized to predicted values at zero magnetic field.
- Found very weak temperature dependence of plateau resistance up to 50 Kelvin.
- Demonstrated a topology-controlled switch with a high on/off ratio of 200.
Conclusions:
- Kink states in Bernal bilayer graphene exhibit robustness and tunability.
- These findings show promise for the development of electron quantum optics devices.
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