Issue
EPL
Volume 87, Number 2, July 2009
Article Number 27008
Number of page(s) 6
Section Condensed Matter: Electronic Structure, Electrical, Magnetic and Optical Properties
DOI http://dx.doi.org/10.1209/0295-5075/87/27008
Published online 18 August 2009
EPL, 87 (2009) 27008
DOI: 10.1209/0295-5075/87/27008

Tunneling transport in a graphene-based ferromagnet/insulator/d-wave superconductor junction

Jianfei Zou and Guojun Jin

National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University Nanjing, 210093, China

gjin@nju.edu.cn

received 2 April 2009; accepted in final form 15 July 2009; published July 2009
published online 18 August 2009

Abstract
We study the electronic transport in a graphene-based ferromagnet/insulator/d-wave superconductor (F/I/S) junction by use of the Dirac-Bogoliubov-de Gennes equation. The effects of spin polarization in the F region, barrier strength in the I region, and Fermi wave vector mismatch between the F and S regions are taken into account. It is found that the differential conductance and shot noise are strongly modulated by these parameters and display different features compared with other junctions. One interesting finding is that, at zero bias voltage and the maximum orientation angle of the superconductive gap $\alpha =\pi /4$, the conductance, shot noise and Fano factor are only controlled by one parameter, i.e. the spin polarization, irrespective of all the other parameters. This universal feature could be applied to measure the magnitude of the spin polarization induced in graphene.

PACS
74.45.+c - Proximity effects; Andreev effect; SN and SNS junctions.
73.50.Td - Noise processes and phenomena.
73.23.Ad - Ballistic transport.

© EPLA 2009