Wurm, Juergen and Rycerz, Adam and Adagideli, Inanc and Wimmer, Michael and Richter, Klaus and Baranger, Harold U. (2009) Symmetry Classes in Graphene Quantum Dots: Universal Spectral Statistics, Weak Localization, and Conductance Fluctuations. PHYSICAL REVIEW LETTERS, 102 (5): 056806. ISSN 0031-9007,
Full text not available from this repository.Abstract
We study the symmetry classes of graphene quantum dots, both open and closed, through the conductance and energy level statistics. For abrupt termination of the lattice, these properties are well described by the standard orthogonal and unitary ensembles. However, for smooth mass confinement, special time-reversal symmetries associated with the sublattice and valley degrees of freedom are critical: they lead to block diagonal Hamiltonians and scattering matrices with blocks belonging to the unitary symmetry class even at zero magnetic field. While the effect of this structure is clearly seen in the conductance of open dots, it is suppressed in the spectral statistics of closed dots, because the intervalley scattering time is shorter than the time required to resolve a level spacing in the closed systems but longer than the escape time of the open systems.
| Item Type: | Article |
|---|---|
| Uncontrolled Keywords: | DISORDERED GRAPHENE; TRANSPORT; CAVITIES; |
| Subjects: | 500 Science > 530 Physics |
| Divisions: | Physics > Institute of Theroretical Physics > Chair Professor Richter > Group Klaus Richter |
| Depositing User: | Dr. Gernot Deinzer |
| Date Deposited: | 05 Oct 2020 12:37 |
| Last Modified: | 05 Oct 2020 12:37 |
| URI: | https://pred.uni-regensburg.de/id/eprint/29478 |
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