Nonlinear order parameter oscillations and lattice coupling in strongly-driven charge-density-wave systems

Abstract

The anharmonic response of charge-density wave (CDW) order to strong laser-pulse perturbations in 1T-TaS_2 and TbTe_3 is investigated by means of a multiple-pump-pulse time-resolved femtosecond optical spectroscopy. We observe remarkable anharmonic effects hitherto undetected in the 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 to the broken symmetry state of the CDW systems.

References in corpus (8)

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Cited by in corpus (8)

• Photoinduced Enhancement of the Charge Density Wave Amplitude
• Incoherent topological defect recombination dynamics in TbTe_3
• Formation of buried domain walls in the ultrafast transition of SmTe${}_3$
• Separating pairing from quantum phase coherence dynamics above the superconducting transition by femtosecond spectroscopy
• Doublon-like excitations and their phononic coupling in a Mott charge-density-wave system
• Ultrafast measurements under anisotropic strain reveal near equivalence of competing charge orders in TbTe${}_3$
• Multichannel photodiode detector for ultrafast optical spectroscopy
• Topical review: the nature of the ground state and possibility of a quantum spin liquid in 1T metal dichalcogenides