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  • Coherent structural dynamic...
    Huber, T; Mariager, S O; Ferrer, A; Schäfer, H; Johnson, J A; Grübel, S; Lübcke, A; Huber, L; Kubacka, T; Dornes, C; Laulhe, C; Ravy, S; Ingold, G; Beaud, P; Demsar, J; Johnson, S L

    Physical review letters, 07/2014, Letnik: 113, Številka: 2
    Journal Article

    Using femtosecond time-resolved x-ray diffraction, we directly monitor the coherent lattice dynamics through an ultrafast charge-density-wave-to-metal transition in the prototypical Peierls system K(0.3)MoO(3) over a wide range of relevant excitation fluences. While in the low fluence regime we directly follow the structural dynamics associated with the collective amplitude mode; for fluences above the melting threshold of the electronic density modulation we observe a transient recovery of the periodic lattice distortion. We can describe these structural dynamics as a motion along the coordinate of the Peierls distortion triggered by the prompt collapse of electronic order after photoexcitation. The results indicate that the dynamics of a structural symmetry-breaking transition are determined by a high-symmetry excited state potential energy surface distinct from that of the initial low-temperature state.