Tunneling transport in a graphene-based ferromagnet/insulator/d-wave superconductor junctionJianfei Zou and Guojun Jin
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University Nanjing, 210093, China
received 2 April 2009; accepted in final form 15 July 2009; published July 2009
published online 18 August 2009
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 , 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.
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