Abstract
We have studied the spin relaxation dynamics in both n- and p-type layered bulk WSe2 under a perpendicular electric field by employing time-resolved Kerr rotation and helicity-resolved transient reflection measurements. The experimental results reveal the efficient tuning of spin relaxation time from 3 ps to 46 ps by the external electric field at 10 K. The dependence of spin relaxation time on the external electric field is understood based on active interlayer hopping. These studies demonstrate the gate-tunable spin polarization and relaxation in bulk transition metal dichalcogenides (TMDCs), which are fundamentally important for understanding spin dynamics and the practical design of spintronic devices based on bulk TMDCs.
Highlights
Two dimensional (2D) transition metal dichalcogenides (TMDCs), such as WSe2, MoS2, MoSe2, and WS2, have emerged as promising materials for optical, electronic, and quantum manipulation applications.1–3 In monolayers, crystal inversion symmetry breaking together with strong spin-orbit coupling (SOC) leads to valley-contrasting spin splitting in both valence and conduction bands.4–7 Via circularly polarized light excitation, a valleycontrasting optical selection rule is allowed for two valleys of A and B excitons
Our experimental results reveal the efficient tuning of spin relaxation time from 3 ps to 46 ps by the external electric field at 10 K. These studies demonstrate gate-tunable spin polarization and relaxation in bulk TMDCs, which are fundamentally important for understanding spin dynamics and the practical design of spintronic devices
By comparing the decaying curve of the circular polarization degree measured by the helicityresolved transient reflectance with that of TRKR response, one can see that the observed spin relaxation by the two experimental methods is consistent, which demonstrates the substantial spin polarization existing in the TMDC bulk crystal
Summary
Two dimensional (2D) transition metal dichalcogenides (TMDCs), such as WSe2, MoS2, MoSe2, and WS2, have emerged as promising materials for optical, electronic, and quantum manipulation applications.1–3 In monolayers, crystal inversion symmetry breaking together with strong spin-orbit coupling (SOC) leads to valley-contrasting spin splitting in both valence and conduction bands.4–7 Via circularly polarized light excitation, a valleycontrasting optical selection rule is allowed for two valleys of A and B excitons. The spin relaxation dynamics in both the n- and p-type layered bulk WSe2 have been systematically examined by time-resolved scitation.org/journal/adv
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
