Spin Transport and Accumulation in 2D Weyl Fermion System

Abstract

In this work, we study the spin Hall effect and Rashba-Edelstein effect of a 2D Weyl fermion system in the clean limit using the Kubo formalism. Spin transport is solely due to the spin-torque current in this strongly spin-orbit coupled (SOC) system, and chiral spin-flip scattering off non-SOC scalar impurities, with potential strength $V$ and size $a$, gives rise to a skew-scattering mechanism for the spin Hall effect. The key result is that the resultant spin-Hall angle has a fixed sign, with ${\theta }^{SH}\sim O\left(\frac{V^2}{v_F^2/a^2}(k_{F}a{)}^4\right)$ being a strongly-dependent function of $k_{F}a$, with $k_F$ and $v_F$ being the Fermi wave-vector and Fermi velocity respectively. This, therefore, allows for the possibility of tuning the SHE by adjusting the Fermi energy or impurity size.

Revised version with inclusion of supplementary information

References in corpus (10)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Dissipationless Quantum Spin Current at Room Temperature
• Spin current and polarization in impure 2D electron systems with spin-orbit coupling
• On A Proper Definition of Spin Current
• Theory of Spin Hall conductivity in n-doped GaAs
• Direct observation of the spin texture in strongly correlated SmB6 as evidence of the topological Kondo insulator
• Electrical detection of the spin polarization due to charge flow in the surface state of the topological insulator Bi_1.5 Sb_0.5 Te_1.7 Se_1.3
• Enhanced spin Hall effect by resonant skew scattering in orbital-selective Kondo effect
• Spin Hall effect of conserved current: Conditions for a nonzero spin Hall current
• Spin-transfer torque and spin-polarization in topological-insulator/ferromagnet vertical heterostructures

Cited by in corpus (4)

• Topological flat band, Dirac fermions and quantum spin Hall phase in 2D Archimedean lattices
• Conserved current of nonconserved quantities
• Critical spin fluctuation mechanism for the spin Hall effect
• Dynamical precession of spin in the two-dimensional spin-orbit coupled systems