Contact conductance between graphene and quantum wires
arXiv:0809.4911 · doi:10.1016/j.physleta.2008.12.015
Abstract
The contact conductance between graphene and two quantum wires which serve as the leads to connect graphene and electron reservoirs is theoretically studied. Our investigation indicates that the contact conductance depends sensitively on the graphene-lead coupling configuration. When each quantum wire couples solely to one carbon atom, the contact conductance vanishes at the Dirac point if the two carbon atoms coupling to the two leads belong to the same sublattice of graphene. We find that such a feature arises from the chirality of the Dirac electron in graphene. Such a chirality associated with conductance zero disappears when a quantum wire couples to multiple carbon atoms. The general result irrelevant to the coupling configuration is that the contact conductance decays rapidly with the increase of the distance between the two leads. In addition, in the weak graphene-lead coupling limit, when the distance between the two leads is much larger than the size of the graphene-lead contact areas and the incident electron energy is close to the Dirac point, the contact conductance is proportional to the square of the product of the two graphene-lead contact areas, and inversely proportional to the square of the distance between the two leads.
References in corpus (23)
- Electric Field Effect in Atomically Thin Carbon Films
- Two-Dimensional Gas of Massless Dirac Fermions in Graphene
- Experimental Observation of Quantum Hall Effect and Berry's Phase in Graphene
- Chiral tunneling and the Klein paradox in graphene
- Electronic Properties of Disordered Two-Dimensional Carbon
- Unconventional Integer Quantum Hall effect in graphene
- Measurement of Scattering Rate and Minimum Conductivity in Graphene
- Weak localisation magnetoresistance and valley symmetry in graphene
- Strong suppression of weak (anti)localization in graphene
- Quantum-limited shot noise in graphene
- Selective transmission of Dirac electrons and ballistic magnetoresistance of \textit{n-p} junctions in graphene
- Phase Coherent Transport of Charges in Graphene Quantum Billiard
- Observation of zigzag and armchair edges of graphite using scanning tunneling microscopy and spectroscopy
- Zitterbewegung, chirality, and minimal conductivity in graphene
- Scanning tunneling microscopy and spectroscopy of the electronic local density of states of graphite surfaces near monoatomic step edges
- Intervalley scattering, long-range disorder, and effective time reversal symmetry breaking in graphene
- Weak antilocalization in epitaxial graphene: evidence for chiral electrons
- On the minimal conductivity of graphene
- Robust Transport Properties in Graphene
- On electron (anti)localization in graphene
- Effective contact model for transport through weakly-doped graphene
- Transport through normal metal - graphene contacts
- Development and Performance of the Nanoworkbench: A Four Tip STM for Electrical Conductivity Measurements Down to Sub-micrometer Scales