Related papers: The definition of the spin current: The angular sp…
We find that in order to completely describe the spin transport, apart from spin current (or linear spin current), one has to introduce the angular spin current. The two spin currents respectively describe the translational and rotational…
For an electron, a spin-1/2 particle, the spin charge $\mathbf{s}$, a real pseudovector with constant length, could determine the spin polarization properties in quantum mechanics. Since spin density $\rho_{\mathbf{s}}$ could be expressed…
The conventional definition of spin current is incomplete and unphysical in describing spin transport in systems with spin-orbit coupling. A proper and measurable spin current is established in this study, which fits well into the standard…
By generalizing the usual current density to a matrix with respect to spin variables, a general equation of continuity satisfied by the density matrix and current density matrix has been derived. This equation holds in arbitrary spin-orbit…
Spin current, a key concept in spintronics that carries spin angular momentum, has a non-unique definition due to the non-conservation of spins in solids. While two primary definitions exist -- conventional spin current and conserved spin…
The spin current $J_{S}$, orbit angular momentum current $J_{L}$ and total angular momentum current $J_{J}$ in a dyad form have been universally defined according to quantum electrodynamics. Their conservation quantities and the continuity…
Starting from a continuum constituted by charged tops, we formulate the classical counterpart of a previously obtained covariant continuity-like equation for the spin current. Such a formulism provides an intuitive picture to elucidate the…
This article discusses spin transport in systems with spin-orbit interactions and how it can be understood in a semiclassical picture. I will first present a semiclassical wave-packet description of spin transport, which explains how the…
In magnets with non-collinear spin configuration the expectation value of the conventionally defined spin current operator contains a contribution which renormalizes an external magnetic field and hence affects only the precessional motion…
The present review analyzes and compares various types of dissipationless spin transport: (1) Superfluid transport, when the spin-current state is a metastable state (a local but not the absolute minimum in the parameter space). (2)…
Along with the progress of spin science and spintronics research, the flow of electron spins, (i.e. spin current), has attracted interest. New phenomena and electronic states were explained in succession using the concept of spin current.…
At each of the boundaries of the two-dimensional (2D) rectangular conductor parallel to the electric current there arises a stripe with an electric field transverse to the current and a 100% electron spin polarization. The two stripes have…
This article reviews steady-state spin densities and spin currents in materials with strong spin-orbit interactions. These phenomena are intimately related to spin precession due to spin-orbit coupling which has no equivalent in the steady…
Spin and charge currents can be generated by an ac voltage through a one-channel quantum wire with strong electron interactions in a static uniform magnetic field. In a certain range of low voltages, the spin current can grow as a negative…
We derive an expression for the spin-current through a tunnel barrier in terms of many-body Green's functions. The spin current has two contributions. One can be associated with angular-momentum transfer by spin-polarized charge currents…
The notion of the spin is shown to have two constituents, as exemplified by the spin of the electron. The first one is related to the form of the wave equation and determines the fermion or boson particle type. This implies the spin taking…
The conventional definition of spin-current, namely spin density multiplied by the group velocity, is not a conserved quantity due to possible spin rotations caused by spin-orbit (SO) interaction. However, in a model with spin-spin…
We theoretically predict that a pure steady state spin-current without charge-current can induce an electric field. A formula for the induced electric field is derived and we investigate its characteristics. Conversely, a moving spin is…
The inductance of spintronic devices that transport charge neutral spin currents is discussed. It is known that in a media that contains charge neutral spins, a time-varying electric field induces a spin current. We show that since the spin…
The spin-orbit coupling systems with a zero magnetic field is studied under the equilibrium situation, {\it i.e.}, without a voltage bias. A persistent spin current is predicted to exist under most circumstances, although the persistent…