Abstract
Spin-orbit coupling (SOC)—a relativistic interaction which entangles a particle’s motion with its quantum mechanical spin—is fundamental to a wide range of physics phenomena, spanning from the formation of topological insulators to the spin Hall effect of light. The last decade has seen remarkable progress in the probing, enhancing and tailoring of SOC in artificial materials, specifically heterostructures, made of two or more individual flakes of graphene-like crystals arranged in a stack. From the electrical control of spin-valley coupling in bilayer graphene[1] to gate-tuneable spin-charge interconversion in graphene placed on atomically thin semiconductors[2], these discoveries challenge our previous notions on the possible behaviour of spin-orbit coupled electrons at interfaces. In this talk, I will focus on recent proposals for probing and exploiting the rich interplay of spin and lattice-pseudospin degrees of freedom afforded by two-dimensional layered materials, including a current-induced spin polarization tuneable by means of a simple interlayer rotation angle[3]. Theoretical developments in the microscopic description of coupled spin-charge transport in realistic disordered systems will be briefly reviewed.
References:
[1] “Anisotropic spin currents in graphene”, https://physics.aps.org/articles/v11/s108
[2] “Optimal charge-to-spin conversion in graphene on transition-metal dichalcogenides”, M. Offidani, M. Milletarì, R. Raimondi, and A. Ferreira. Phys. Rev. Lett. 119 (2017); “Gate-tunable reversible Rashba−Edelstein effect in a few-layer Graphene/2H-TaS2 heterostructure at room temperature“, L. Li et al. ACS Nano 14 (2020); “Proposal for unambiguous electrical detection of spin-charge conversion in lateral spin valves”, S. A. Cavill, C. Huang, M. Offidani, Y.-H. Lin, M. A. Cazalilla and A. Ferreira, Phys. Rev. Lett. 124 (2020)
[3] “Twist angle controlled collinear Edelstein effect in van der Waals heterostructures”, A. Veneri, D. T. S. Perkins, C. G. Péterfalvi, and A. Ferreira. Phys. Rev. B 106, L081406 (2022)