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Updated: Jun 3, 2026
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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Size effects in Aharonov-Bohm graphene rings
1Quantum Optoelectronics Laboratory, Southwest Jiaotong University, Chengdu, People's Republic of China.
Summary
Persistent currents in graphene rings exhibit unique behaviors, differing from metal rings. These Aharonov-Bohm effects show size-dependent oscillations, suggesting room-temperature experimental tests.
Area of Science:
- Condensed Matter Physics
- Mesoscopic Physics
- Graphene Nanostructures
Background:
- Aharonov-Bohm (AB) effects are well-documented in mesoscopic metal rings.
- Persistent currents (PCs) are crucial in understanding quantum phenomena in confined systems.
Purpose of the Study:
- Investigate Aharonov-Bohm effects on persistent currents in a closed graphene ring.
- Explore the influence of broken time-reversal symmetry on these currents.
- Analyze size-dependent properties of persistent currents in graphene rings.
Main Methods:
- Numerical calculation of induced persistent currents.
- Application of hard boundary conditions for Dirac electrons in a ring.
- Analysis of persistent current properties in relation to ring dimensions.
Main Results:
- Graphene ring PCs lack the saw-tooth features and odd-even electron number symmetry seen in metal rings.
- PCs exhibit oscillating behavior with amplitude dependent on ring radius and width.
- Energy difference between valleys and PC amplitude correlate inversely with ring radius and directly with width.
Conclusions:
- Persistent currents in graphene rings display distinct characteristics compared to metal rings.
- Size-dependent persistent currents and Aharonov-Bohm effects in graphene rings are tunable.
- Findings suggest feasibility of room-temperature experimental verification of these phenomena.
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