2018/11/14 by Jonas Wätzel, Jamal Berakdar
Computer Science · Physics and Astronomy · #Condensed matter physics #Electron #Ferromagnetism #Laser #Mechanical and Optical Resonators #Optics #Physics #Quantum Hall effect #Quantum Information and Cryptography #Quantum mechanics #Quantum optics and atomic interactions #Quantum spin Hall effect #Spin (aerodynamics) #Spin Hall effect #Spin engineering #Spin polarization #Spin pumping #Spinplasmonics #Spintronics #Ultrashort pulse #cond-mat.mes-hall #quant-ph
paper · pdf · doi:10.1038/s41598-018-35378-4
published as Scientific Reports 8, 17102 (2018) · 12 pages, 6 figures
openalex publication_date 2018/11/14 · arxiv created 2018/11/23 · arxiv updated 2018/11/26 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/05
Spin Hall effect, one of the cornerstones in spintronics refers to the emergence of an imbalance in the spin density transverse to a charge flow in a sample under voltage bias. This study points to a novel way for an ultrafast generation and tuning of a unidirectional nonlinear spin Hall current by means of subpicosecond laser pulses of optical vortices. When interacting with matter, the optical orbital angular momentum (OAM) carried by the vortex and quantified by its topological charge is transferred to the charge carriers. The residual spin-orbital coupling in the sample together with confinement effects allow exploiting the absorbed optical OAM for spatio-temporally controlling the spin channels. Both the non-linear spin Hall current and the dynamical spin Hall angle increase for a higher optical topological charge. The reason is the transfer of a higher amount of OAM and the enhancement of the effective spin-orbit interaction strength. No bias voltage is needed. We demonstrate that the spin Hall current can be all-optically generated in an open circuit geometry for ring-structured samples. These results follow from a full-fledged propagation of the spin-dependent quantum dynamics on a time-space grid coupled to the phononic environment. The findings point to a versatile and controllable tool for the ultrafast generation of spin accumulations with a variety of applications such as a source for ultrafast spin transfer torque and charge and spin current pulse emitter.