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Charge Neutral Current Generation in a Spontaneous Quantum Hall Antiferromagnet
Miuko Tanaka1, Yuya Shimazaki2, Ivan Valerievich Borzenets3
1Department of Applied Physics, University of Tokyo, Tokyo, 113-8656, Japan.
Physical Review Letters
|January 22, 2021
Summary
Researchers generated a charge neutral current in bilayer graphene without breaking inversion symmetry. This challenges previous understanding and opens new avenues for spintronics research.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Phenomena
Background:
- The intrinsic Hall effect enables nondissipative, charge-neutral currents like pure spin currents via the spin Hall effect.
- Generating such currents typically requires breaking spatial inversion or time-reversal symmetries, or strong spin-orbit interaction.
Purpose of the Study:
- To challenge the conventional requirement of symmetry breaking for generating charge-neutral currents.
- To demonstrate the generation and detection of a charge-neutral current in a material lacking strong spin-orbit interaction and spatial inversion symmetry.
Main Methods:
- Utilizing bilayer graphene as the material system.
- Investigating transport properties within the quantum Hall antiferromagnetic state.
Main Results:
- Successfully generated and detected a charge-neutral current in bilayer graphene.
- Observed enhanced nonlocal transport phenomena.
- Identified spontaneous symmetry breaking driven by electronic correlations in the quantum Hall antiferromagnetic state.
Conclusions:
- Demonstrated that charge-neutral currents can be generated without traditional symmetry breaking.
- Highlighted the role of electronic correlations and spontaneous symmetry breaking in centrosymmetric materials.
- Opened new possibilities for creating charge-neutral currents in materials with weak spin-orbit coupling.
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