How to Distinguish between Specular and Retroconfigurations for Andreev Reflection in Graphene Rings
Abstract
We numerically investigate Andreev reflection in a graphene ring with one normal conducting and one superconducting lead by solving the Bogoliubov--de Gennes equation within the Landauer-B\"uttiker formalism. By tuning chemical potential and bias voltage, it is possible to switch between regimes where electron and hole originate from the same band (retroconfiguration) or from different bands (specular configuration) of the graphene dispersion, respectively. We find that the dominant contributions to the Aharonov-Bohm conductance oscillations in the subgap transport are of period in retroconfiguration and of period in specular configuration, confirming the predictions obtained from a qualitative analysis of interfering scattering paths. Because of the robustness against disorder and moderate changes to the system, this provides a clear signature to distinguish both types of Andreev reflection processes in graphene.
Keywords
Cite
@article{arxiv.1110.4383,
title = {How to Distinguish between Specular and Retroconfigurations for Andreev Reflection in Graphene Rings},
author = {Jörg Schelter and Björn Trauzettel and Patrik Recher},
journal= {arXiv preprint arXiv:1110.4383},
year = {2012}
}
Comments
5 pages, 5 figures. arXiv admin note: substantial text overlap with arXiv:1201.6200