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arXiv · 2106.11839

Electrical control of orbital and vibrational interlayer coupling in bi- and trilayer 2H-MoS$_2$

Julian Klein·Jakob Wierzbowski·Pedro Soubelet·Thomas Brumme·Lorenzo Maschio·Agnieszka Kuc·Kai Müller·Andreas V. Stier·Jonathan J. Finley
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Abstract

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-MoS$_2$ 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 $\sim 60\%$ in bilayer and $\sim 35\%$ in trilayer MoS$_2$ 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.

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Julian Klein, Jakob Wierzbowski, Pedro Soubelet, Thomas Brumme, Lorenzo Maschio, Agnieszka Kuc, Kai Müller, Andreas V. Stier, Jonathan J. Finley. 2021-06-22. Electrical control of orbital and vibrational interlayer coupling in bi- and trilayer 2H-MoS$_2$. https://doi.org/10.1103/physrevmaterials.6.024002

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