摘要Four-component Bogoliubov--de Gennes equations are applied to study the tunnelling conductance spectra G(E) of half-metallic ferromagnet/ferromagnet/s-wave superconductor tunnel junctions. It is found that only for noncollinear magnetizations, there exists nonzero G(E) structure within the energy gap, which is a signature of appearance of the novel Andreev reflection and spin-triplet pairing correlations.
Abstract：Four-component Bogoliubov--de Gennes equations are applied to study the tunnelling conductance spectra G(E) of half-metallic ferromagnet/ferromagnet/s-wave superconductor tunnel junctions. It is found that only for noncollinear magnetizations, there exists nonzero G(E) structure within the energy gap, which is a signature of appearance of the novel Andreev reflection and spin-triplet pairing correlations.
[1]Zutic I and Valls O T 1999 Phys. Rev. B 60 6320 [2] Zutic I and Valls O T 2000 Phys. Rev. B 611555 [3] Zhu J X and Ting C S 2000 Phys. Rev. B 61 1456 [4] Bergeret F S, Volkov A F and Efetov K B 2005 Rev.Mod. Phys. 77 1321 [5] Kashiwaya S and Tanaka Y 2000 Rep. Prog. Phys. 63 1641 [6] Kikuchi K, Imamura H, Takahashi S and Maekawa S 2002 Phys. Rev. B 65 020508 [7] Andreev A F 1964 Sov. Phys. JETP 19 1228 [8] Golubov A A, Kupriyanov M Yu and Ll'ichev E 2004 Rev.Mod. Phys. 76 411 [9] Keizer R S, Goennenwein S T B, Klapwijk T M, Miao G, XiaoG and Gupta A 2006 Nature 439 825 [10] Bergeret F S, Volkov A F and Efetov K B 2001 Phys.Rev. Lett. 86 4096 [11] Linder J and Sudb$\phi$ A 2007 Phys. Rev. B 75 134509 [12] Volkov A F, Bergeret F S and Efetov K B 2003 Phys.Rev. Lett. 90 117006 [13]\"{ofwander T L, Champel T, Durst J and Eschrig M 2005 Phys. Rev. Lett. 95 187003 [14] Niu Z P and Xing D Y 2007 Phys. Rev. Lett. 98057005 [15] Blonder G E, Tinkham M and Klapwijk T M 1982 Phys.Rev. B 25 4515 [16] Yokoyama T, Tanaka Y and Inoue J 2006 Phys. Rev. B 74 035318 [17] Molenkamp L W, Schmidt G and Bauer G E W 2001 Phys.Rev. B 64 121202(R) [18] Kadigrobov A, Shekhter R I and Jonson M 2001 Europhys. Lett. 54 394 Kadigrobov A, Shekhter R I and Jonson M 2001 Low Temp.Phys. 27 760 [19] Krivoruchko V N, Tarenkov V Yu, D'yachenko A I andVaryukhin V N 2006 Europhys. Lett. 75 294 [20] D'yachenko A I, Krivoruchko V N and Tarenkov V Yu 2006 Low Temp. Phys. 32 824
2008, Vol. 25 
