Speaker
Description
The spin-orbit torque (SOT) mechanism offers new avenues for magnetic technologies, where spin-orbit coupling (SOC) at a metal-magnet interface is harnessed to electrically manipulate the magnetic state. Van der Waals materials emerge as a natural SOT platform due to their layered structure, where furthermore SOC and magnetic properties can be tailored by proximity effects. However, low SOT efficiencies and the need for experimentally challenging low-symmetry materials still hinder their progress, requiring new developments to further boost the efficiency and control of SOT mechanisms.
In this work we unveil novel SOT and charge-to-spin conversion mechanisms due to intra-particle entanglement between spin and pseudospin in graphene-based heterostructures [1, 2]. We begin demonstrating the manipulation of spin-pseudospin entanglement by tuning different forms of proximity-induced SOC. By these means we achieve charge-to-spin conversion of maximal efficiency in non-magnetic graphene via the Rashba-Edelstein effect (also called inverse spin galvanic effect). Upon proximitizing a magnetic layer, additional SOT mechanisms originated within the Fermi sea are enabled. Using a semi-classical theory for the non-equilibrium spin dynamics we trace the breakdown of the semi-classical behavior due to predominance of quantum spin-pseudospin entanglement, leading to an enhanced SOT regime. Here, we unveil a novel SOT contribution which emerges within the topological gap of the quantum anomalous Hall phase. Overall, our results reveal that intertwined spin-pseudospin mechanisms lead to novel SOT phenomena which may serve to further tailor spintronic technologies.
References
[1] J. Medina Dueñas, J.H. Garcia and S. Roche, Phys. Rev. Lett. 132, 266301 (2024)
[2] J. Medina Dueñas, J.H. Garcia and S. Roche, arXiv:2408.16359 (2024)
