Light-Induced Transient Polarization Reversal in Rhombohedrally Stacked Bilayer Transition Metal Dichalcogenides via an Electronic Mechanism
Abstract
Light-induced sliding ferroelectricity in two-dimensional van der Waals materials enables polarization control via relative layer motion. However, polarization switching occurs on the time scale of shear modes (tens of ps) and requires very large fluences, potentially damaging the samples. Here, using constrained density functional theory and many-body real-time simulations, we demonstrate an ultrafast electronic reversal of the total out-of-plane polarization sign in the photoexcited state, without requiring interlayer sliding, in rhombohedrally stacked transition-metal dichalcogenide bilayers. The polarization changes sign relative to its initial ground-state value at moderate fluences and within ∼ 200 fs, about 50 times faster than the typical shear-mode period. The ultrafast switching is driven by a rearrangement of localized dipoles around the tungsten sites. We establish a novel general mechanism for electronic control of low-dimensional ferroelectrics common to all polar multilayers having type II band alignment. Our work has direct implications for ultrahigh-speed volatile optical memory operating on sub-ps time scales.
Versions
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BibTeX
@misc{zhu2026lightinduced,
title = {{Light-Induced Transient Polarization Reversal in Rhombohedrally Stacked Bilayer Transition Metal Dichalcogenides via an Electronic Mechanism}},
author = {Xiangzhou Zhu and Stefano Mocatti and Matteo Calandra},
howpublished = {arXiv},
year = {2026},
month = sep,
doi = {10.48550/arxiv.2605.25982},
eprint = {2605.25982},
archivePrefix = {arXiv},
url = {https://arxiv.org/abs/2605.25982},
note = {CC BY 4.0},
}
RIS
TY - UNPB
TI - Light-Induced Transient Polarization Reversal in Rhombohedrally Stacked Bilayer Transition Metal Dichalcogenides via an Electronic Mechanism
AU - Xiangzhou Zhu
AU - Stefano Mocatti
AU - Matteo Calandra
PY - 2026
DA - 2026/09/03
PB - arXiv
DO - 10.48550/arxiv.2605.25982
UR - https://arxiv.org/abs/2605.25982
AB - Light-induced sliding ferroelectricity in two-dimensional van der Waals materials enables polarization control via relative layer motion. However, polarization switching occurs on the time scale of shear modes (tens of ps) and requires very large fluences, potentially damaging the samples. Here, using constrained density functional theory and many-body real-time simulations, we demonstrate an ultrafast electronic reversal of the total out-of-plane polarization sign in the photoexcited state, without requiring interlayer sliding, in rhombohedrally stacked transition-metal dichalcogenide bilayers. The polarization changes sign relative to its initial ground-state value at moderate fluences and within ∼ 200 fs, about 50 times faster than the typical shear-mode period. The ultrafast switching is driven by a rearrangement of localized dipoles around the tungsten sites. We establish a novel general mechanism for electronic control of low-dimensional ferroelectrics common to all polar multilayers having type II band alignment. Our work has direct implications for ultrahigh-speed volatile optical memory operating on sub-ps time scales.
ER -