  We study the room-temperature electrical control of charge and spin transport
in high-quality bilayer graphene, fully encapsulated with hBN and contacted via
1D spin injectors. We show that spin transport in this device architecture is
measurable at room temperature and its spin transport parameters can be
modulated by opening of a band gap via a perpendicular displacement field. The
modulation of the spin current is dominated by the control of the spin
relaxation time with displacement field, demonstrating the basic operation of a
spin-based field-effect transistor.
