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arXiv · 0909.1289

Raman scattering evidence for a cascade-like evolution of the charge-density-wave collective amplitude mode

M. Lavagnini·H. -M. Eiter·L. Tassini·B. Muschler·R. Hackl·R. Monnier·J. -H. Chu·I. R. Fisher·L. Degiorgi
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Abstract

The two-dimensional rare-earth tri-tellurides undergo a unidirectional charge-density-wave (CDW) transition at high temperature and, for the heaviest members of the series, a bidirectional one at low temperature. Raman scattering experiments as a function of temperature on DyTe$_3$ and on LaTe$_3$ at 6 GPa provide a clear-cut evidence for the emergence of the respective collective CDW amplitude excitations. In the unidirectional CDW phase, we surprisingly discover that the amplitude mode develops as a succession of two mean-field, BCS-like transitions in different temperature ranges.

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M. Lavagnini, H. -M. Eiter, L. Tassini, B. Muschler, R. Hackl, R. Monnier, J. -H. Chu, I. R. Fisher, L. Degiorgi. 2009-09-07. Raman scattering evidence for a cascade-like evolution of the charge-density-wave collective amplitude mode. https://doi.org/10.1103/physrevb.81.081101

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