We use helicity-resolved ultrafast transient absorption spectroscopy to study spin-valley polarization dynamics in a vertically stacked MoSe2/WSe2 heterostructure. The experimental findings reveal details of interlayer charge transfer on ultrafast timescales, showing that the spin-valley polarized state of photoexcited carriers is conserved during the charge transfer and formation of interlayer excitons. Our results confirm that phonon scattering mediates the interlayer charge transfer process, while a high phonon population at elevated temperatures causes a significant decrease in spin-valley selective charge transfer. Moreover, the experimental findings demonstrate the possibility that interlayer excitons and their spin-valley polarization can be probed in the optical response of intralayer excitons. These findings pave the way for ultrafast detection, control, and manipulation of spin-valley polarized excitons in transition metal dichalcogenide-based 2D heterostructures.
@article{arxiv.2411.14180,
title = {Unveiling Ultrafast Spin-Valley Dynamics and Phonon-Mediated Charge Transfer in MoSe$_{2}$/WSe$_{2}$ Heterostructures},
author = {Julian Wagner and Robin Bernhardt and Lukas Rieland and Omar Abdul-Aziz and Qiuyang Li and Xiaoyang Zhu and Stefano Dal Conte and Giulio Cerullo and Paul H. M. van Loosdrecht and Hamoon Hedayat},
journal= {arXiv preprint arXiv:2411.14180},
year = {2024}
}