Semiclassical conservation of spin and large transverse spin current in Dirac systems
arXiv:1812.04493 · doi:10.1103/PhysRevLett.122.187703
Abstract
In Dirac materials, the low energy excitations obey the relativistic Dirac equation. This dependence implies that the electrons are exposed to strong spin-orbit coupling. Hence, real spin conservation is believed to be violated in Dirac materials. We show that this point of view needs to be refined in the semiclassical picture which applies to the case of doped Dirac materials (away from the nodal point in the spectrum). We derive a novel type of Boltzmann equation for these systems if they are brought slightly out-of-equilibrium. Remarkably, spin-momentum locking is softened and a generalized spin conservation law can be formulated. The most striking observable consequence of our theory is a large transverse spin current in a nearly ballistic transport regime.
arXiv comment9 pages, 2 figures
References in corpus (20)
- The electronic properties of graphene
- Topological Insulators
- Topological insulators and superconductors
- Weyl and Dirac Semimetals in Three Dimensional Solids
- Carrier transport in 2D graphene layers
- A self-consistent theory for graphene transport
- Wave-packet dynamics in slowly perturbed crystals: Gradient corrections and Berry-phase effects
- Dirac materials
- Quantum Hall Ferromagnetism in Graphene
- Quantum transport of massless Dirac fermions in graphene
- Electron scattering on microscopic corrugations in graphene
- On A Proper Definition of Spin Current
- Quantum critical transport in clean graphene
- Semiclassical theory of spin transport in spin-orbit coupled systems
- Quantum-critical relativistic magnetotransport in graphene
- Inverse Spin Hall Effect from pulsed Spin Current in Organic Semiconductors with Tunable Spin-Orbit Coupling
- Dirac Surface States and Nature of Superconductivity in Noncentrosymmetric BiPd
- Generalized kinetic equations for charge carriers in graphene
- Quantum kinetic equation and universal conductance fluctuations in graphene
- Relativistic Gurzhi effect in channels of Dirac materials