  The ability to engineer new states of matter and to control their electronic
and spintronic properties by electric fields is at the heart of the modern
information technology and driving force behind recent advances in van der
Waals (vdW) heterostructures of two-dimensional materials. Here, we exploit a
proximity-induced Rashba-Edelstein (REE) effect in vdW heterostructures of Weyl
semimetal candidate MoTe2 and CVD graphene, where an unprecedented
gate-controlled switching of spin-galvanic effect emerges due to an efficient
spin-to-charge conversion at room temperature. The magnitude of the measured
spin-galvanic signal is found to be an order of magnitude larger than the other
systems, giving rise to a giant REE. The magnitude and the sign of the
spin-galvanic signal are shown to be strongly modulated by gate electric field
near the charge neutrality point, which can be understood considering the spin
textures of the Rashba spin-orbit coupling-induced spin-splitting in conduction
and valence bands of the heterostructure. These findings open opportunities for
utilization of gate-controlled switching of spin-galvanic effects in spintronic
memory and logic technologies and possibilities for realization of new states
of matter with novel spin textures in vdW heterostructures with gate-tunable
functionalities.
