Nature and Raman signatures of the Higgs amplitude mode in the coexisting superconducting and charge-density-wave state

Autor:	Cea, T., Benfatto, L.
Rok vydání:	2014
Předmět:	Condensed Matter - Superconductivity
Zdroj:	Phys. Rev. B 90, 224515 (2014)
Druh dokumentu:	Working Paper
DOI:	10.1103/PhysRevB.90.224515
Popis:	We investigate the behavior of the Higgs (amplitude) mode when superconductivity emerges on a preexisting charge-density-wave state. We show that the weak overdamped square-root singularity of the amplitude fluctuations in a standard BCS superconductor is converted in a sharp, undamped power-law divergence in the coexisting state, reminiscent of the Higgs behavior in Lorentz-invariant theories. This effect reflects in a strong superconducting resonance in the Raman spectra, both for an electronic and a phononic mechanism leading to the Raman visibility of the Higgs. In the latter case, our results are relevant to the interpretation of the Raman spectra measured experimentally in NbSe2. Comment: Extended version, accepted for publication in PRB
Databáze:	arXiv
Externí odkaz:	http://arxiv.org/abs/1407.6497 Zobrazit plný text záznamu View this record from Arxiv