Manipulating electronic interlayer coupling in layered van der Waals (vdW) materials is essential for designing opto-electronic devices. Here, we control vibrational and electronic interlayer coupling in bi- and trilayer 2H-MoS2 using large external electric fields in a micro-capacitor device. The electric field lifts Raman selection rules and activates phonon modes in excellent agreement with ab-initio calculations. Through polarization resolved photoluminescence spectroscopy in the same device, we observe a strongly tunable valley dichroism with maximum circular polarization degree of ∼60% in bilayer and ∼35% in trilayer MoS2 that are fully consistent with a rate equation model which includes input from electronic band structure calculations. We identify the highly delocalized electron wave function between the layers close to the high symmetry Q points as the origin of the tunable circular dichroism. Our results demonstrate the possibility of electric field tunable interlayer coupling for controlling emergent spin-valley physics and hybridization driven effects in vdW materials and their heterostructures.
@article{arxiv.2106.11839,
title = {Electrical control of orbital and vibrational interlayer coupling in bi- and trilayer 2H-MoS$_2$},
author = {Julian Klein and Jakob Wierzbowski and Pedro Soubelet and Thomas Brumme and Lorenzo Maschio and Agnieszka Kuc and Kai Müller and Andreas V. Stier and Jonathan J. Finley},
journal= {arXiv preprint arXiv:2106.11839},
year = {2023}
}