Josephson coupling through ferromagnetic heterojunctions with noncollinear magnetizations
BUZDIN, Alexandre I.
Centre de physique moléculaire optique et hertzienne [CPMOH]
Institut universitaire de France [IUF]
< Leer menos
Centre de physique moléculaire optique et hertzienne [CPMOH]
Institut universitaire de France [IUF]
Idioma
en
Article de revue
Este ítem está publicado en
Physical Review B: Condensed Matter and Materials Physics (1998-2015). 2006, vol. 74, n° 18, p. 184509 (7)
American Physical Society
Resumen en inglés
We study the Josephson effect in clean heterojunctions that consist of superconductors connected through two metallic ferromagnets with insulating interfaces. We solve the scattering problem based on the Bogoliubov--de ...Leer más >
We study the Josephson effect in clean heterojunctions that consist of superconductors connected through two metallic ferromagnets with insulating interfaces. We solve the scattering problem based on the Bogoliubov--de Gennes equation for any relative orientation of in-plane magnetizations, arbitrary transparency of interfaces, and mismatch of Fermi wave vectors. Both spin singlet and triplet superconducting correlations are taken into account, and the Josephson current is calculated as a function of the ferromagnetic layers thicknesses and of the angle $\alpha$ between their magnetizations. We find that the critical Josephson current $I_c$ is a monotonic function of $\alpha$ when the junction is far enough from $0-\pi$ transitions. This holds when ferromagnets are relatively weak. For stronger ferromagnets, variation of $\alpha$ induces switching between 0 and $\pi$ states and $I_c(\alpha)$ is non-monotonic function, displaying characteristic dips at the transitions. However, the non-monotonicity is the effect of a weaker influence of the exchange potential in the case of non-parallel magnetizations. No substantial impact of spin-triplet superconducting correlations on the Josephson current has been found in the clean limit. Experimental control of the critical current and $0-\pi$ transitions by varying the angle between magnetizations is suggested.< Leer menos
Orígen
Importado de HalCentros de investigación