Cross-dimensional electron-phonon coupling in van der Waals heterostructures

• Published in: Nature communications Vol. 10; no. 1; p. 2419
• Main Authors: Lin, Miao-Ling, Zhou, Yu, Wu, Jiang-Bin, Cong, Xin, Liu, Xue-Lu, Zhang, Jun, Li, Hai, Yao, Wang, Tan, Ping-Heng
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 03.06.2019; Nature Publishing Group; Nature Portfolio
• Subjects: 140/133; 639/301/357/1018; 639/766/119/995; Coupling; Crystals; Electrons; Heterostructures; Humanities and Social Sciences; Interlayers; multidisciplinary; Phonons; Polarizability; Science; Science (multidisciplinary); Spectrum analysis
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-019-10400-z

The electron-phonon coupling (EPC) in a material is at the frontier of the fundamental research, underlying many quantum behaviors. van der Waals heterostructures (vdWHs) provide an ideal platform to reveal the intrinsic interaction between their electrons and phonons. In particular, the flexible van der Waals stacking of different atomic crystals leads to multiple opportunities to engineer the interlayer phonon modes for EPC. Here, in hBN/WS 2 vdWH, we report the strong cross-dimensional coupling between the layer-breathing phonons well extended over tens to hundreds of layer thick vdWH and the electrons localized within the few-layer WS 2 constituent. The strength of such cross-dimensional EPC can be well reproduced by a microscopic picture through the mediation by the interfacial coupling and also the interlayer bond polarizability model in vdWHs. The study on cross-dimensional EPC paves the way to manipulate the interaction between electrons and phonons in various vdWHs by interfacial engineering for possible interesting physical phenomena. The strength of electron-phonon coupling can be directly probed by Raman spectroscopy. Here, the authors use low-frequency Raman spectroscopy to unveil the existence of a strong cross-dimensional coupling between the bulk-like layer-breathing phonons in an hBN/WS2 heterostructure and the electrons localized within its few-layer WS2 constituent.