All-Electric Spin Device Operation Using the Weyl Semimetal, WTe2, at Room Temperature

Topological quantum materials (TQMs) possess abundant and attractive spin physics, and a Weyl semimetal is the representative material because of the generation of spin polarization that is available for spin devices due to its Weyl nature. Meanwhile, a Weyl semimetal allows the other but unexplored spin polarization due to local symmetry breaking. Here, all-electric spin device operation using a type-II Weyl semimetal, WTe2, at room temperature is reported. The polarization of spins propagating in the all-electric device is perpendicular to the WTe2 plane, which is ascribed to local in-plane symmetry breaking in WTe2, yielding the spin polarization creation of propagating charged carriers, namely, the spin-polarized state creation from the nonpolarized state. Systematic control experiments unequivocally negate unexpected artifacts, such as the anomalous Hall effect, the anisotropic magnetoresistance, etc. Creation of all-electric spin devices made of TQMs and their operation at room temperature can pave a new pathway for novel spin devices made of TQMs resilient to thermal fluctuation.