Coexistence of superconductivity and ferromagnetism in ferromagnet/superconductor proximity structures
National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University, Nanjing 210093, PR China
2 Department of Physics, The Chinese University of Hong Kong, Hong Kong, PR China
Corresponding author: a email@example.com
Published online: 19 November 2002
The Nambu spinor Green's function approach is applied to calculating the density of states (DOS) and superconducting order parameter in normal-metal/insulator/ferromagnet/superconductor (NM/I/FM/SC) junctions. It is found that the s-wave superconductivity and ferromagnetism can coexist near the FM/SC interface, which is induced by proximity effect. On the SC side, the spin-dependent DOS appears both within and without the energy gap. On the FM side, the superconducting order parameter displays a damped oscillation and the DOS exhibits some superconducting behavior. The calculated result for the DOS in FM for “0 state” and “π state” can reproduce recent tunneling spectra in Al/Al2O3/PdNi/Nb tunnel junctions.
PACS: 74.50.+r – Proximity effects, weak links, tunneling phenomena, and Josephson effects / 74.80.Fp – Point contacts; SN and SNS junctions / 74.80.-g – Spatially inhomogeneous structures
© EDP Sciences, Società Italiana di Fisica, Springer-Verlag, 2002