Intervalley mixing of interface excitons at lateral heterojunctions

Fuente: arXiv
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Autori principali: Durnev, M. V., Smirnov, D. S.
Natura: Preprint
Pubblicazione: 2024
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author Durnev, M. V.
Smirnov, D. S.
author_facet Durnev, M. V.
Smirnov, D. S.
contents $\require{mediawiki-texvc}$ We demonstrate that the low symmetry of armchair lateral heterojunction between transition metal dichalcogenide monolayers allows for the mixing of $\mathbf{K}_+$ and $\mathbf{K}_-$ valleys. From the tight binding model we estimate the strength of the valley coupling to be of the order of $0.2$ eV$\cdotÅ$ for typical heteropairs. We show that the valley mixing gives rise to the in-plane $g$-factor of localized electrons leading to the spin precession in the in-plane magnetic field. We further study the effects of the valley mixing on the fine structure and dynamics of excitons at type-II lateral heterojunctions. We find that the interplay of the valley mixing and long-range exchange interaction leads to the linear polarization of exciton photoluminescence along the armchair heterojunction with the degree of polarization up to $1/3$ under unpolarized excitation. Application of the in-plane magnetic field of the order of 10$-$100 mT in any direction leads to the depolarization of the photoluminescence.
format Preprint
id arxiv_https___arxiv_org_abs_2408_10170
institution arXiv
publishDate 2024
record_format arxiv
spellingShingle Intervalley mixing of interface excitons at lateral heterojunctions
Durnev, M. V.
Smirnov, D. S.
Mesoscale and Nanoscale Physics
Materials Science
$\require{mediawiki-texvc}$ We demonstrate that the low symmetry of armchair lateral heterojunction between transition metal dichalcogenide monolayers allows for the mixing of $\mathbf{K}_+$ and $\mathbf{K}_-$ valleys. From the tight binding model we estimate the strength of the valley coupling to be of the order of $0.2$ eV$\cdotÅ$ for typical heteropairs. We show that the valley mixing gives rise to the in-plane $g$-factor of localized electrons leading to the spin precession in the in-plane magnetic field. We further study the effects of the valley mixing on the fine structure and dynamics of excitons at type-II lateral heterojunctions. We find that the interplay of the valley mixing and long-range exchange interaction leads to the linear polarization of exciton photoluminescence along the armchair heterojunction with the degree of polarization up to $1/3$ under unpolarized excitation. Application of the in-plane magnetic field of the order of 10$-$100 mT in any direction leads to the depolarization of the photoluminescence.
title Intervalley mixing of interface excitons at lateral heterojunctions
topic Mesoscale and Nanoscale Physics
Materials Science
url https://arxiv.org/abs/2408.10170