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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Localization and the Kosterlitz-Thouless transition in disordered graphene
Yan-Yang Zhang1, Jiangping Hu, B A Bernevig
1Department of Physics, Purdue University, West Lafayette, Indiana 47907, USA.
Physical Review Letters
|April 28, 2009
Summary
Strong disorder in graphene causes states near Dirac points to localize, contrary to expectations. This localization transition, driven by current vortices, is of the Kosterlitz-Thouless type.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Graphene is a 2D material with unique electronic properties governed by Dirac fermions.
- Disorder in materials can significantly alter electronic states, often leading to localization.
- Prevailing theories suggested delocalization in disordered 2D Dirac systems.
Purpose of the Study:
- To investigate the electronic state behavior in disordered graphene with strong long-range impurities.
- To challenge the prevailing belief of persistent delocalization in such systems.
- To characterize the nature of the transition between localized and delocalized states.
Main Methods:
- Theoretical investigation of disordered graphene.
- Analysis of electronic states near Dirac points.
- Characterization of the disorder-induced transition mechanism.
Main Results:
- States near Dirac points localize for strong disorder, contradicting prior assumptions.
- Intervalley scattering is inevitable in the localized regime.
- The localization-delocalization transition is identified as Kosterlitz-Thouless type.
Conclusions:
- Strong disorder fundamentally alters electronic behavior in graphene.
- The transition is driven by the dynamics of local current vortices.
- Graphene's electronic properties are more sensitive to disorder than previously thought.
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