Related Experiment Video
Updated: May 26, 2026
11:42
Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Quantum finite-size effects in graphene plasmons.
Sukosin Thongrattanasiri1, Alejandro Manjavacas, F Javier García de Abajo
1IQFR-CSIC, Serrano 119, 28006 Madrid, Spain.
ACS Nano
|January 6, 2012
Summary
Graphene plasmons behave classically down to 10 nm, but quantum effects emerge in smaller structures. Finite-size and edge effects significantly influence plasmon properties in graphene nanostructures.
Area of Science:
- Condensed matter physics
- Materials science
- Nanophotonics
Background:
- Graphene plasmons offer tunable, long-lived alternatives to noble metal plasmons.
- Current models use classical electrodynamics, representing graphene as a local conductivity.
- The accuracy of classical descriptions and the impact of quantum effects in small graphene structures remain unclear.
Purpose of the Study:
- To determine the minimum size of graphene nanostructures where classical descriptions of plasmons remain accurate.
- To investigate the influence of nonlocal and quantum finite-size effects on graphene plasmons.
- To elucidate the role of edge structure in plasmon properties of graphene nanostructures.
Main Methods:
- First-principles calculations of optical response.
- Tight-binding model for electronic structure.
- Random-phase approximation for dielectric response.
Main Results:
- Classical local electromagnetic theory accurately describes graphene plasmons down to approximately 10 nm.
- Below 10 nm, plasmons exhibit multiple resonances, highlighting molecular character and quantum effects.
- Finite-size effects cause significant plasmon broadening in nanodisks (>20 nm) and nanoribbons (>10 nm).
- Zigzag edges contribute more to plasmon broadening than armchair edges.
Conclusions:
- Graphene nanostructures support well-defined plasmons even below 10 nm.
- Finite-size and nonlocal effects are crucial for understanding plasmon characteristics in nanoscale graphene.
- This work provides a foundation for the field of graphene nanoplasmonics.
