Intrinsic effect of interfacial coupling on the high-frequency intralayer modes in twisted multilayer MoTe2
Author(s): Leng, YC (Leng, Yu-Chen); Lin, ML (Lin, Miao-Ling); Zhou, Y (Zhou, Yu); Wu, JB (Wu, Jiang-Bin); Meng, D (Meng, Da); Cong, X (Cong, Xin); Li, H (Li, Hai); Tan, PH (Tan, Ping-Heng)
Source: NANOSCALE DOI: 10.1039/d1nr01309b Early Access Date: APR 2021
Abstract: The interfacial coupling at the interface makes the van der Waals heterostructures (vdWHs) exhibit many unique properties that cannot be realized in its constituents. Such a study usually starts with a twisted stack of two flakes exfoliated from the same layered materials to form twisted multilayers, in which the impact of interfacial coupling on the low-frequency interlayer modes had been well understood. However, it is not clear how interfacial coupling affects the high-frequency intralayer modes of twisted multilayers. Herein, we perform high-resolution resonance Raman spectroscopy of the high-frequency intralayer modes in twisted multilayer MoTe2 (tMLM). All the Davydov entities of the out-of-plane intralayer mode are observed and distinguished at 4 K. It is found that the out-of-plane intralayer modes in tMLM are sensitive to its interfacial layer-breathing coupling so that the out-of-plane intralayer modes in tMLM do not show a direct relationship with those of the two constituents. However, the case is quite different for the in-plane intralayer modes in tMLM, whose spectral profile can be fitted by those of the corresponding modes of its constituents. This indicates that the in-plane intralayer modes are localized within the constituents in tMLM because of its negligible interfacial shear coupling at the interface. All the results can be well understood using the vdW model in which only the nearest neighbor interlayer/interfacial interaction is taken into account. This work directly builds the relationship between the Davydov splitting of the high-frequency intralayer vibrations and the low-frequency interlayer vibrations in tMLM, which can be further extended to other twisted materials and the related vdWHs.
Accession Number: WOS:000652675300001
PubMed ID: 34019059
Author Identifiers:
Author Web of Science ResearcherID ORCID Number
Tan, Ping-Heng D-1137-2009 0000-0001-6575-1516
Lin, Miao-Ling T-7309-2017 0000-0001-5838-8237
ISSN: 2040-3364
eISSN: 2040-3372
Full Text: https://pubs.rsc.org/en/content/articlelanding/2021/NR/D1NR01309B#!divAbstract