  Quantum materials with a large charge current-induced spin polarization are
promising for next-generation all-electrical spintronic science and technology.
Van der Waals metals with high spin-orbit coupling and novel spin textures have
attracted significant attention for an efficient charge to spin conversion
process. Here, we demonstrate the electrical generation of spin polarization in
NbSe2 up to room temperature. To probe the current-induced spin polarization in
NbSe2, we used a graphene-based non-local spin-valve device, where the
spin-polarization in NbSe2 is efficiently injected and detected using non-local
spin-switch and Hanle spin precession measurements. A significantly higher
charge-spin conversion in NbSe2 is observed at a lower temperature, below the
superconducting transition temperature Tc ~ 7 K of NbSe2. However, the
charge-spin conversion signal could only be observed with a higher bias current
above the superconducting critical current, limiting the observation of the
signal only to the non-superconducting state of NbSe2. Systematic measurements
provide the possible origins of the spin polarization to be predominantly due
to the spin Hall effect or Rashba-Edelstein effect in NbSe2, considering
different symmetry allowed charge-spin conversion processes.
