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Updated: May 19, 2026
11:42
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Voltage-driven ring confinement in a graphene sheet: assessing conditions for bound state solutions.
Leonardo Villegas-Lelovsky1, Carlos Trallero-Giner, Victor Lopez-Richard
1Departamento de Física, Universidade Federal de São Carlos, São Carlos, São Paulo, Brazil. lvl@df.ufscar.br
Nanotechnology
|September 6, 2012
Summary
We studied quantum rings in graphene, controlling electron and hole states with voltage. This research maps how to tune optical properties from metallic to semiconductor phases.
Area of Science:
- Condensed matter physics
- Materials science
- Quantum mechanics
Background:
- Graphene quantum rings offer tunable electronic properties.
- Understanding single-particle states is crucial for device applications.
Purpose of the Study:
- To systematically study single-particle states in graphene quantum rings.
- To map the character of electron and hole quasi-particle solutions.
- To describe conditions for controlling bound states and optical properties.
Main Methods:
- Simulations using the Dirac Hamiltonian within the envelope function approximation.
- Modeling potential profiles from concentric circular gates on graphene.
- Considering graphene-substrate interactions.
Main Results:
- Microscopic mapping of quasi-particle solutions based on applied voltage.
- Identification of general conditions to control bound states.
- Demonstration of tunable optical properties (metallic to semiconductor phases).
- Observation of contrasting behaviors for attractive/repulsive voltages and coupling strengths.
Conclusions:
- Voltage control enables tuning of graphene quantum ring properties.
- The study provides a framework for designing optoelectronic devices based on graphene quantum rings.
- Graphene-substrate coupling significantly influences quantum ring behavior.
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