2010/06/30 by P. Kusar, T. Mertelj, V. V. Kabanov +5 · 1 citation
Earth and Planetary Sciences · Engineering · Materials Science · Physics and Astronomy · #Amplitude #Anharmonicity #Coupling (piping) #Excitation #Excited state #Femtosecond #High-pressure geophysics and materials #Laser #Laser Material Processing Techniques #Organic and Molecular Conductors Research #Phonon #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.83.035104
published as Phys. Rev. B 83, 035104 (2011)
arxiv created 2010/10/08 · openalex publication_date 2011/01/10 · arxiv updated 2012/09/03 · openalex created_date 2016/06/24 · openalex updated_date 2026/08/05
The anharmonic response of charge-density wave (CDW) order to strong laser-pulse perturbations in 1 T\ensuremath-TaS2 and TbTe3 is investigated by means of multiple-pump-pulse time-resolved femtosecond optical spectroscopy. We observe remarkable anharmonic effects hitherto undetected in systems exhibiting collective charge ordering. The efficiency for additional excitation of the amplitude mode by a laser pulse becomes periodically modulated after the mode is strongly excited into a coherently oscillating state. A similar effect is observed also for some other phonons, where the cross-modulation at the amplitude-mode frequency indicates anharmonic interaction of those phonons with the amplitude mode. By analyzing the observed phenomena in the framework of time-dependent Ginzburg-Landau theory we attribute the effects to the anharmonicity of the mode potentials inherent in the broken symmetry state of the CDW systems.