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arXiv · 2401.07703

Polaron-induced changes in moir\'e exciton propagation in twisted van der Waals heterostructures

Willy Knorr·Samuel Brem·Giuseppe Meneghini·Ermin Malic
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Abstract

Twisted transition metal dichalcogenides (TMDs) present an intriguing platform for exploring excitons and their transport properties. By introducing a twist angle, a moir\'e superlattice forms, providing a spatially dependent exciton energy landscape. Based on a microscopic many-particle theory, we investigate in this work polaron-induced changes in exciton transport properties in the MoSe$_2$/WSe$_2$ heterostructure. We demonstrate that polaron formation and the associated enhancement of moir\'e excitonic mass lead to a significant band flattening. As a result, the hopping rate and the propagation velocity undergo noticeable temperature and twist-angle dependent changes. We predict a reduction of the hopping strength ranging from 80% at a twist angle of 1$^\circ$ to 30% at 3$^\circ$ at room temperature. The provided microscopic insights into the spatio-temporal exciton dynamics in presence of a moir\'e potential further deepens our understanding of the intriguing moir\'e exciton physics.

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Willy Knorr, Samuel Brem, Giuseppe Meneghini, Ermin Malic. 2024-01-15. Polaron-induced changes in moir\'e exciton propagation in twisted van der Waals heterostructures. https://arxiv.org/abs/2401.07703

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