The spin-polarized tunnel current and the spin-transfer torque in triple-barrier junctions with external electrodes and quantum wells made of ferromagnetic materials

•The normal spin torque is significantly enhanced when the magnetic moments in the inner layers are not collinearly oriented.•Hybridized quantum-well states in the inner layer significantly affect the charge current and spin torque.•Angular dependence of the torque in triple junctions can be more co...

Ausführliche Beschreibung

Gespeichert in:
Bibliographische Detailangaben
Veröffentlicht in:Journal of magnetism and magnetic materials 2023-08, Vol.580, p.170901, Article 170901
Hauptverfasser: Wilczyński, M., Zberecki, K., Wierzbicki, M.
Format: Artikel
Sprache:eng
Schlagworte:
Online-Zugang:Volltext
Tags: Tag hinzufügen
Keine Tags, Fügen Sie den ersten Tag hinzu!
Beschreibung
Zusammenfassung:•The normal spin torque is significantly enhanced when the magnetic moments in the inner layers are not collinearly oriented.•Hybridized quantum-well states in the inner layer significantly affect the charge current and spin torque.•Angular dependence of the torque in triple junctions can be more complex than in single junctions. The electron transport in triple-barrier junctions consisting of external ferromagnetic layers and three non-magnetic barriers separated by two inner ferromagnetic layers is analysed. It is assumed that the magnetic moments in the external electrodes are oriented in the same direction, whereas the magnetic moments of the inner layers can form any angle with this direction. The possibility of the gigantic enhancement of the normal torque component has been found in the junctions with a non-colinear orientation of magnetic moments in the inner layers. This enhancement may be much larger than in the double junctions. The current and the in-plane torque are most amplified when the quantum-well states in both inner layers have similar energies and can form the complex resonant states located slightly below the Fermi level. When the tunnelling by these complex resonant states occurs, the torque is greatest in the magnetic configuration other than that where the current is maximally enhanced. Additionally, the angular dependence of the torque differs significantly from that observed in single tunnel junctions.
ISSN:0304-8853
DOI:10.1016/j.jmmm.2023.170901