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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Two-dimensional graphene with structural defects: elastic mean free path, minimum conductivity, and Anderson
Aurélien Lherbier1, Simon M-M Dubois, Xavier Declerck
1Institute of Condensed Matter and Nanoscience (IMCN), Université Catholique de Louvain (UCL), Louvain-la-Neuve, Belgium.
Physical Review Letters
|March 17, 2011
Summary
Disordered graphene with structural defects exhibits quantum transport properties. Conductivity saturates at high defect densities, and Anderson localization may be measurable at low defect levels.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Graphene's unique electronic properties are sensitive to structural defects.
- Understanding quantum transport in disordered graphene is crucial for electronic applications.
Purpose of the Study:
- Investigate quantum transport in graphene with Stone-Wales and divacancy defects.
- Determine the impact of defect nature and density on conductivity and localization.
Main Methods:
- Utilized a realistic π-π* tight-binding model derived from ab initio calculations.
- Employed an order-N real-space Kubo-Greenwood method to compute transport properties.
- Calculated mean free paths and semiclassical conductivities as a function of defect density.
Main Results:
- Semiclassical conductivities predicted to saturate at a minimum value (4e2/πh) with increasing defect density.
- This saturation occurs over a broad carrier density range (>0.5×10^14 cm^-2).
- Quantum interference effects suggest Anderson localization is potentially measurable at defect densities as low as 1%.
Conclusions:
- Structural defects significantly influence quantum transport in graphene.
- Graphene's conductivity exhibits a robust minimum value under high defect concentrations.
- Anderson localization in graphene is experimentally accessible at low defect levels, opening avenues for novel electronic devices.
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