Coherent quantum transport in ferromagnet/s±‐wave superconductor/ferromagnet structures

We extend the Blonder–Tinkham–Klapwijk approach to studying the effects of barrier strength and spin polarization on coherent spin‐polarized transport in ferromagnet (FM)/iron‐pnictide‐superconductor (SC)/FM structures with s±‐paring for the SC. It is demonstrated that the effects of barrier strength and spin polarization on the particular features of oscillations of all the reflection and transmission probabilities, and differential conductances with energy in ferromagnetic and antiferromagnetic alignments of the magnetizations of the two FMs are different, which are also different from those for the s++ model.

[1]  M. Machida,et al.  Theory of heterotic superconductor-insulator-superconductor Josephson junctions between single- and multiple-gap superconductors. , 2009, Physical review letters.

[2]  M. Tortello,et al.  Three-band s± Eliashberg theory and the superconducting gaps of iron pnictides , 2009, 0904.1808.

[3]  S. Onari,et al.  Surface density of states of s ± -wave Cooper pairs in a two-band superconductor model , 2009, 0901.1166.

[4]  I. Mazin,et al.  Andreev spectra and subgap bound states in multiband superconductors. , 2008, Physical review letters.

[5]  J. Linder,et al.  Theory of Andreev reflection in junctions with iron-based high- T c superconductors , 2008, 0811.1775.

[6]  M. Norman.  High-temperature superconductivity in the iron pnictides , 2008 .

[7]  Jian Kang,et al.  Spin fluctuation dynamics and multiband superconductivity in iron pnictides , 2008, 0809.0014.

[8]  Guizhen Wu,et al.  Superconductivity at 43 K in SmFeAsO1-xFx , 2008, Nature.

[9]  S. Blundell,et al.  Coexistence of magnetic fluctuations and superconductivity in the pnictide high temperature superconductor SmFeAsO1-xFx measured by muon spin rotation. , 2008, Physical review letters.

[10]  Chaoxing Liu,et al.  Minimal two-band model of the superconducting iron oxypnictides , 2008, 0804.1113.

[11]  Jingguo Hu,et al.  Coherent transport and andreev reflection in ferromagnetic semiconductor/superconductor/ ferromagnetic semiconductor double tunneling junctions , 2005 .

[12]  G. Deutscher.  Andreev–Saint-James reflections: A probe of cuprate superconductors , 2004, cond-mat/0409225.

[13]  Zhenghan Wang,et al.  Coherent quantum transport in ferromagnet/superconductor/ferromagnet structures , 2003 .

[14]  T. M. Klapwijk,et al.  Transition from metallic to tunneling regimes in superconducting microconstrictions: Excess current, charge imbalance, and supercurrent conversion , 1982 .