Spin-Hall effect of collimated electrons in zinc-blende semiconductors

We describe an intrinsic spin-Hall effect (SHE) in n-type bulk zinc-blende semiconductors with a topological origin. When a collimated flux of electrons is injected into a zinc-blende semiconductor with Dresselhaus spin-orbit interaction, a nontrivial gauge structure appears in the momentum k→- space of the electrons. The Berry curvature of this gauge field and the corresponding Lorentz force in k→-space results in a finite SHE. The value of the spin-Hall current is found to be highly dependent on the degree of electron collimation, which may be varied by means of gate electrodes. Therefore, the system may potentially be useful as an electronically controllable source of pure spin-current for spintronic applications.