The zero-bias conductance of quantum dots coupled to ferromagnetic leads is investigated. In the strong-coupling regime, it is found that the conductance is a non-monotonic function of the angle between the magnetisation directions in the two contacts. This behaviour is an effect of the presence of the leads which induces an angle-dependent spin-split of the quantum dot states, and spin-flip transitions between the quantum dot states whenever the magnetisation directions of the leads are non-collinear, which enhances the current density at the chemical potential. In the weak-coupling regime, the system reverts to normal spin valve character.
EPL (Europhysics Letters)
- Pub Date:
- June 2005
- Condensed Matter - Mesoscale and Nanoscale Physics;
- Condensed Matter - Strongly Correlated Electrons
- 4 pages, 4 figures. Europhysics Letters (accepted)