期刊
PHYSICAL REVIEW B
卷 79, 期 11, 页码 -出版社
AMER PHYSICAL SOC
DOI: 10.1103/PhysRevB.79.115131
关键词
d-wave superconductivity; graphene; nanostructured materials; tight-binding calculations
资金
- NANOFRIDGE
- EU Project
- CNR-INFM
- Programma Rientro Cervelli
We study Andreev reflection in graphene nanoribbon/superconductor hybrid junctions. By using a tight-binding approach and the scattering formalism we show that finite-size effects lead to notable differences with respect to the bulk-graphene case. At subgap voltages, conservation of pseudoparity, a quantum number characterizing the ribbon states, yields either a suppression of Andreev reflection when the ribbon has an even number of sites in the transverse direction or perfect Andreev reflection when the ribbon has an odd number of sites. In the former case the suppression of Andreev reflection induces an insulating behavior even when the junction is biased; electron conduction can however be restored by applying a gate voltage. Finally, we check that these findings remain valid also in the case of nonideal nanoribbons in which the number of transverse sites varies along the transport direction.
作者
我是这篇论文的作者
点击您的名字以认领此论文并将其添加到您的个人资料中。
推荐
暂无数据