  Ferromagnetic materials are the widely used source of spin-polarized
electrons in spintronic devices, which are controlled by external magnetic
fields or spin-transfer torque methods. However, with increasing demand for
smaller and faster spintronic components, utilization of spin-orbit phenomena
provides promising alternatives. New materials with unique spin textures are
highly desirable since all-electric creation and control of spin polarization
is expected, where the strength, as well as an arbitrary orientation of the
polarization, can be defined without the use of a magnetic field. In this work,
we use a novel spin-orbit crystal BiTeBr for this purpose. Owning to its giant
Rashba spin splitting, bulk spin polarization is created at room temperature by
an electric current. Integrating BiTeBr crystal into graphene-based spin valve
devices, we demonstrate for the first time that it acts as a current-controlled
spin injector, opening new avenues for future spintronic applications in
integrated circuits.
