Theory of conserved spin current and its application to two dimensional hole gas

Abstract

We present a detailed microscopic theory of the conserved spin current which is introduced by us [Phys. Rev. Lett. \textbf{96}, 196602 (2006)] and satisfies the spin continuity equation even for spin-orbit coupled systems. The spin transport coefficients ${\sigma }_{\mu \nu }^s$ as a response to the electric field are shown to consist of two parts, i.e., the conventional part ${\sigma }_{\mu \nu }^{s0}$ and the spin torque dipole correction ${\sigma }_{\mu \nu }^{s\tau }$. As one key result, an Onsager relation between ${\sigma }_{\mu \nu }^s$ and other kinds of transport coefficients are shown. The expression for ${\sigma }_{\mu \nu }^s$ in terms of single-particle Bloch states are derived, by use of which we study the conserved spin Hall conductivity in the two dimensional hole gas modeled by a combined Luttinger and SIA Rashba spin-orbit coupling. It is shown that the two components in spin Hall conductivity usually have the opposite contributions. While in the absence of Rashba spin splitting, the spin Hall transport is dominated by the conventional contribution, the presence of Rashba spin splitting stirs up a large enhancement of the spin torque dipole correction, leading to an overall sign change for the total spin Hall conductivity. Furthermore, an approximate two-band calculation and the subsequent comparison with the exact four-band results are given, which reveals that the coupling between the heavy hole and light hole bands should be taken into account for strong Rashba spin splitting.

10 pages, 4 figures

References in corpus (10)

• Dissipationless Quantum Spin Current at Room Temperature
• On A Proper Definition of Spin Current
• SU(2) Non-Abelian Holonomy and Dissipationless Spin Current in Semiconductors
• Sign Changes of Intrinsic Spin Hall Effect in Semiconductors and Simple Metals: First-Principles Calculations
• Spin-Hall transport of heavy holes in III-V semiconductor quantum wells
• Quasiclassical approach to the spin-Hall effect in the two-dimensional electron gas
• Spin transport in Heisenberg antiferromagnets
• Spin Hall effect of conserved current: Conditions for a nonzero spin Hall current
• Boundary spin Hall effect in a two-dimensional semiconductor system with Rashba spin-orbit coupling
• On boundary conditions for spin diffusion equations with Rashba spin-orbit interaction

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• Calculation of current-induced torque from spin continuity equation
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• Spin-Hall effect due to the bulk states of topological insulators: Extrinsic contribution to the conserved spin current
• Orbital Hall effect in transition metals from first-principles scattering calculations
• Effect of vertex corrections on the enhancement of Gilbert damping in spin pumping into a two-dimensional electron gas
• Interplay between quantum dissipation and an in-plane magnetic field in the spin ratchet effect
• Spin-Hall effect in topological materials: Evaluating the proper spin current in systems with arbitrary degeneracies
• Elasto-Dynamical Induced Spin and Charge Pumping in Bulk Heavy Metals
• Local spin Hall conductivity
• From charge to spin: analogies and differences in quantum transport coefficients
• Spin accumulation in the spin Nernst effect
• Magneto-nonlinear Hall effect in time-reversal breaking system
• Coherence Control of Directional Nonlinear Photocurrent in Spatially Symmetric Systems
• Berry Phase origin of the planar spin Hall effect