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The recent discovery of strongly correlated phases in twisted transition-metal dichalcogenides (TMDs) highlights the significant impact of twist-induced modifications on electronic structures. In this study, we employed angle-resolved photoemission spectroscopy with submicrometer spatial resolution (μ-ARPES) to investigate these modifications by comparing valence band structures of twisted (5.3°) and nontwisted (AB-stacked) bilayer regions within the same WSe device. Relative to the nontwisted region, the twisted area exhibits pronounced moiré bands and ∼90 meV renormalization at the Γ-valley, substantial momentum separation between different layers, and an absence of flat bands at the K-valley. We further simulated the effects of lattice relaxation, which can flatten the Γ-valley edge but not the K-valley edge. Our results provide a direct visualization of twist-induced modifications in the electronic structures of twisted TMDs and elucidate their valley-dependent responses to lattice relaxation.
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http://dx.doi.org/10.1021/acs.nanolett.3c01672 | DOI Listing |
The advent of layered materials has unveiled new opportunities for tailoring electromagnetic waves at the subwavelength scale, particularly through the study of polaritons, a hybrid light-matter excitation. In this context, twist-optics, which investigates the optical properties of twisted stacks of van der Waals (vdW) layered specimens, has emerged as a powerful tool. Here, we explore the tunability of phonon polaritons in α-VO via interlayer twisting using scanning nano-infrared (IR) imaging.
View Article and Find Full Text PDFAdv Mater
November 2024
State Key Laboratory of Medicinal Chemical Biology, Key Laboratory of Functional Polymer Materials, College of Chemistry, Nankai University, 94 Weijin Road, Tianjin, 300071, China.
Nano Lett
August 2023
School of Physical Science and Technology, ShanghaiTech University, Shanghai 201210, People's Republic of China.
The recent discovery of strongly correlated phases in twisted transition-metal dichalcogenides (TMDs) highlights the significant impact of twist-induced modifications on electronic structures. In this study, we employed angle-resolved photoemission spectroscopy with submicrometer spatial resolution (μ-ARPES) to investigate these modifications by comparing valence band structures of twisted (5.3°) and nontwisted (AB-stacked) bilayer regions within the same WSe device.
View Article and Find Full Text PDFNPJ Comput Mater
October 2023
Department of Molecular Chemistry and Materials Science, Weizmann Institute of Science, Rehovot, 7610001 Israel.
Moiré superlattices of transition metal dichalcogenide (TMD) heterostructures give rise to rich excitonic phenomena associated with the interlayer twist angle. Theoretical calculations of excitons in such systems are typically based on model moiré potentials that mitigate the computational cost. However, predictive understanding of the electron-hole coupling dominating the excitations is crucial to realize the twist-induced modifications of the optical selection rules.
View Article and Find Full Text PDFCancer Lett
January 2020
Fudan University Shanghai Cancer Center, Key Laboratory of Medical Epigenetics and Metabolism, Institutes of Biomedical Sciences, Fudan University, Shanghai, 200032, China. Electronic address:
Metastasis is a core hallmark of cancer that leads to high mortality of cancer patients, especially in hepatocellular carcinoma (HCC). However, the underlying mechanisms of long noncoding RNAs (lncRNAs) in HCC metastasis remain largely unknown. We found that ID2-AS1 expression decreased in metastatic HCC cell lines and HCC tissues, and lower ID2-AS1 expression predicted reduced overall survival in HCC patients.
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