Layered 2D van der Waals materials, such as transition metal dichalcogenides, are promising for nanoscale spintronic and optoelectronic applications. Harnessing their full potential requires understanding both intrinsic transport and the dynamics of optically excited spin and charge carriers -- particularly the transition between excited spin polarization and the conduction band's intrinsic spin texture. Here, we investigate the spin polarization of the conduction bands of bulk WSe2 using static and time-resolved spin-resolved photoemission spectroscopy, complemented by photocurrent calculations. Electron doping reveals the intrinsic spin polarization, while time-resolved measurements trace the evolution of excited spin carriers. We find that intervalley scattering is spin-conserving, with spin transport initially governed by photoexcited carriers and aligning with the intrinsic conduction band polarization after ∼150 fs.
@article{arxiv.2506.00161,
title = {Transition from Optically Excited to Intrinsic Spin Polarization in WSe$_2$},
author = {Sebastian Hedwig and Gregor Zinke and Jürgen Braun and Benito Arnoldi and Aki Pulkkinen and Ján Minár and Hubert Ebert and Martin Aeschlimann and Benjamin Stadtmüller},
journal= {arXiv preprint arXiv:2506.00161},
year = {2025}
}