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arXiv · 1401.1025

Amplitude `Higgs' mode in 2H-NbSe2 Superconductor

M. -A. Méasson·Y. Gallais·M. Cazayous·B. Clair·P. Rodière·L. Cario·A. Sacuto
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Abstract

We report experimental evidences for the observation of the superconducting amplitude mode, so-called `Higgs' mode in the charge density wave superconductor 2H-NbSe2 using Raman scattering. By comparing 2H-NbSe2 and its iso-structural partner 2H-NbS2 which shows superconductivity but lacks the charge density wave order, we demonstrate that the superconducting mode in 2H-NbSe2 owes its spectral weight to the presence of the coexisting charge density wave order. In addition, temperature dependent measurements in 2H-NbSe2 show a full spectral weight transfer from the charge density wave mode to the superconducting mode upon entering the superconducting phase. Both observations are fully consistent with a superconducting amplitude mode or Higgs mode.

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M. -A. Méasson, Y. Gallais, M. Cazayous, B. Clair, P. Rodière, L. Cario, A. Sacuto. 2014-01-06. Amplitude `Higgs' mode in 2H-NbSe2 Superconductor. https://doi.org/10.1103/physrevb.89.060503

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