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Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities
Published on: July 24, 2015
Energy-driven drag at charge neutrality in graphene
Justin C W Song1, Leonid S Levitov
1Department of Physics, Massachusetts Institute of Technology, Cambridge, Massachusetts 02139, USA.
Physical Review Letters
|February 2, 2013
Summary
Coulomb coupling in graphene heterostructures enables vertical energy transfer, significantly impacting charge transport. This novel mechanism, particularly prominent near zero doping, offers new experimental diagnostics for graphene systems.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Nanotechnology
Background:
- Graphene heterostructures exhibit Coulomb coupling, leading to vertical energy transfer between electron layers.
- Correlated density inhomogeneity in proximal graphene layers influences lateral charge transport dynamics.
Purpose of the Study:
- To investigate the impact of vertical energy transfer on lateral charge transport in graphene heterostructures.
- To differentiate Coulomb drag from conventional momentum drag and identify experimental signatures.
Main Methods:
- Theoretical analysis of Coulomb coupling and energy transfer in multi-layer graphene.
- Modeling of lateral charge transport influenced by vertical energy dynamics.
- Analysis of doping and temperature dependencies for drag mechanisms.
Main Results:
- Vertical energy transfer significantly affects lateral charge transport, especially with correlated density inhomogeneity.
- Coulomb drag dominates over momentum drag near zero doping in these systems.
- Distinct doping and temperature dependencies differentiate the two drag mechanisms.
Conclusions:
- The study identifies a new Coulomb drag mechanism in graphene heterostructures.
- Distinct experimental features, including a zero-doping peak and sign reversals, are predicted.
- These features can serve as diagnostics for the novel drag mechanism and energy transfer processes.
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