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Space dependent Fermi velocity in strained graphene.
Fernando de Juan1, Mauricio Sturla, María A H Vozmediano
1Department of Physics, Indiana University, Bloomington, Indiana 47405, USA.
Physical Review Letters
|September 26, 2012
Summary
Discrepancies between curved graphene models are resolved. Strained graphene exhibits space-dependent Fermi velocity, impacting experiments. A generalized tight-binding approach reveals a consistent gauge field.
Area of Science:
- Condensed Matter Physics
- Quantum Field Theory
- Materials Science
Background:
- Investigating discrepancies between tight-binding/elasticity and quantum field theory models for curved graphene.
- Understanding the behavior of electrons in curved and strained graphene materials.
Purpose of the Study:
- Reconcile apparent differences in theoretical models for curved graphene.
- Analyze the impact of strain and corrugation on graphene's electronic properties.
- Generalize theoretical frameworks to describe inhomogeneous strain in graphene.
Main Methods:
- Comparison of tight-binding/elasticity theory with quantum field theory in curved space.
- Analysis of space-dependent Fermi velocity in strained/corrugated graphene.
- Generalization of the tight-binding approach for inhomogeneous strain.
Main Results:
- Demonstrated space-dependent Fermi velocity in strained graphene, affecting experimental interpretations.
- Identified a gauge field in the generalized tight-binding approach proportional to strain derivative.
- Showed formal equivalence of the gauge field with that from the covariant approach.
Conclusions:
- The two models for curved graphene are reconcilable.
- Space-dependent Fermi velocity is a key feature of strained graphene, crucial for experimental analysis.
- The generalized tight-binding model provides a unified description of gauge fields in strained graphene.
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