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Tunable Luttinger liquid physics in biased bilayer graphene
Matthew Killi1, Tzu-Chieh Wei, Ian Affleck
1Department of Physics, University of Toronto, Toronto, Ontario, M5S1A7, Canada.
Physical Review Letters
|September 28, 2010
Summary
Electronically gated bilayer graphene exhibits tunable semiconducting properties. Applying a spatially varying bias creates one-dimensional chiral modes that behave as a strongly interacting Tomonaga-Luttinger liquid.
Area of Science:
- Condensed Matter Physics
- Materials Science
- Quantum Mechanics
Background:
- Bilayer graphene under uniform bias acts as a tunable gap semiconductor.
- Spatially varying bias is key to creating novel electronic states.
Purpose of the Study:
- Investigate the behavior of one-dimensional (1D) chiral modes in bilayer graphene under spatially varying bias.
- Characterize the electronic interactions and properties of these 1D modes.
Main Methods:
- Theoretical modeling of bilayer graphene with a spatially varying interlayer bias.
- Incorporation of Coulomb repulsion and gate voltage-dependent electronic properties.
- Analysis of low-energy wave function spread and electron interactions.
Main Results:
- Spatially varying bias induces 1D chiral modes localized at the bias domain wall.
- Forward scattering Coulomb repulsion is the dominant interaction for these 1D electrons.
- These modes exhibit characteristics of a strongly interacting Tomonaga-Luttinger liquid.
Conclusions:
- The 1D chiral modes in bilayer graphene behave as a Tomonaga-Luttinger liquid.
- The system displays three distinct mode velocities and a bias-dependent Luttinger parameter.
- Experimental signatures for these strongly interacting 1D modes are discussed.
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