http://hdl.handle.net/20.500.12128/23763
Tytuł: | First-principles insights into the spin-valley physics of strained transition metal dichalcogenides monolayers |
Autor: | Faria Junior, Paulo E. Zollner, Klaus Woźniak, Tomasz Kurpas, Marcin Gmitra, Martin Fabian, Jaroslav |
Słowa kluczowe: | spin-valley; valley Zeeman; spin-mixing; TMDC; valleytronics; straintronics; strain |
Data wydania: | 2022 |
Źródło: | "New Journal of Physics" (2022), Vol. 24,art. no. 083004 |
Abstrakt: | Transition metal dichalcogenides (TMDCs) are ideal candidates to explore the manifestation of spin-valley physics under external stimuli. In this study, we investigate the influence of strain on the spin and orbital angular momenta, effective g-factors, and Berry curvatures of several monolayer TMDCs (Mo andWbased) using a full ab initio approach. At the K-valleys, we find a surprising decrease of the conduction band spin expectation value for compressive strain, consequently increasing the dipole strength of the dark exciton by more than one order of magnitude (for ∼1%–2% strain variation).We also predict the behavior of direct excitons g-factors under strain: tensile (compressive) strain increases (decreases) the absolute value of g-factors. Strain variations of ∼1% modify the bright (A and B) excitons g-factors by ∼0.3(0.2) forW(Mo) based compounds and the dark exciton g-factors by ∼0.5 (0.3) forW (Mo) compounds. Our predictions could be directly visualized in magneto-optical experiments in strained samples at low temperature. Additionally, our calculations strongly suggest that strain effects are one of the possible causes of g-factor fluctuations observed experimentally. By comparing the different TMDC compounds, we reveal the role of spin–orbit coupling (SOC): the stronger the SOC, the more sensitive are the spin-valley features under applied strain. Consequently, monolayerWSe2 is a formidable candidate to explore the role of strain on the spin-valley physics.We complete our analysis by considering the side valleys, Γ and Q points, and by investigating the influence of strain in the Berry curvature. In the broader context of valley- and strain-tronics, our study provides fundamental microscopic insights into the role of strain in the spin-valley physics of TMDCs, which are relevant to interpret experimental data in monolayer TMDCs as well as TMDC-based van der Waals heterostructures. |
URI: | http://hdl.handle.net/20.500.12128/23763 |
DOI: | 10.1088/1367-2630/ac7e21 |
ISSN: | 1367-2630 |
Pojawia się w kolekcji: | Artykuły (WNŚiT) |
Plik | Opis | Rozmiar | Format | |
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Kurpas_first_rinciplest_insights_into.pdf | 3,7 MB | Adobe PDF | Przejrzyj / Otwórz |
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