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arXiv · 1805.03580

Spectroscopic signature of the $\mathbf{k}$-dependent electron-phonon coupling in $2H$-TaS$_2$

K. Wijayaratne·J. Zhao·C. D. Malliakas·D. Y. Chung·M. G. Kanatzidis·U. Chatterjee
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Abstract

Our detailed Angle Resolved Photoemission Spectroscopy (ARPES) study of $2H$-TaS$_2$, a canonical incommensurate charge density wave (CDW) material, illustrates pronounced many-body renormalization in the system, which is manifested by the presence of multiple kink structures in the electronic dispersions. Temperature-dependent measurements reveal that these kink structures persist even at temperatures higher than the charge density wave transition temperature $\it{T}_{\text{cdw}}\,$ and the energy locations of the kinks are practically temperature-independent. Correlating kink energies with the published Raman scattering data and the theoretically calculated phonon spectrum of $2H$-TaS$_2$, we conclude phononic mechanism for these kinks. We have also detected momentum-anisotropy in the band renormalization, which in turn indicates momentum-dependence of the electron-phonon coupling of the system.

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K. Wijayaratne, J. Zhao, C. D. Malliakas, D. Y. Chung, M. G. Kanatzidis, U. Chatterjee. 2018-05-09. Spectroscopic signature of the $\mathbf{k}$-dependent electron-phonon coupling in $2H$-TaS$_2$. https://doi.org/10.1039/c7tc02641b

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