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arXiv · 2310.06979

Modulating spin-valley relaxation in WSe$_2$ with variable thickness VOPc layers

Daphné Lubert-Perquel·Byeong Wook Cho·Alan J. Philips·Young Hee Lee·Jeffrey L. Blackburn·Justin C. Johnson
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Abstract

Combining the synthetic tunability of molecular compounds with the optical selection rules of transition metal dichalcogenides (TMDC) that derive from spin-valley coupling could provide interesting opportunities for the readout of quantum information. However, little is known about the electronic and spin interactions at such interfaces and the influence on spin-valley relaxation. In this work, vanadyl phthalocyanine (VOPc) molecular layers are thermally evaporated on WSe$_2$ to explore the effect of molecular layer thickness on excited-state spin-valley polarization. The thinnest molecular layer supports an interfacial state which destroys the spin-valley polarization almost instantaneously, whereas a thicker molecular layer results in longer-lived spin-valley polarization than the WSe$_2$ monolayer alone. The mechanism appears to involve a tightly-bound species at the molecule/TMDC interface that strengthens exchange interactions and is largely avoided in thicker VOPc layers that isolate electrons from WSe$_2$ holes.

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Daphné Lubert-Perquel, Byeong Wook Cho, Alan J. Philips, Young Hee Lee, Jeffrey L. Blackburn, Justin C. Johnson. 2023-10-10. Modulating spin-valley relaxation in WSe$_2$ with variable thickness VOPc layers. https://doi.org/10.1063/5.0238993

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