1206.5743 (H. Y. Liu et al.)

Impulsive excitation of coherent amplitudon and phason oscillations in
the K0.3MoO3 charge density wave    [PDF]

H. Y. Liu, J. C. Petersen, S. Kaiser, A. Simoncig, I. Gierz, A. L. Cavalieri, C. Cacho, I. C. E. Turcu, E. Springate, F. Frassetto, L. Poletto, S. S. Dhesi, Z. -A. Xu, T. Cuk, A. Cavalleri

Using time- and angle-resolved photoemission spectroscopy at extreme ultra-violet wavelengths, we have investigated the momentum-dependent dynamics of the electronic structure of photostimulated blue bronze (K0.3MoO3), a quasi-one-dimensional charge density wave (CDW) material. After the CDW gap melts, an amplitude mode oscillation at 1.7 THz modulates the gap in the bonding band. More surprisingly, the anti-bonding band gap is instead modulated at 0.8 THz. We attribute this effect to the non-Raman-active CDW phase mode, coherently excited by anharmonic dynamics in the strongly driven order parameter.

View original: http://arxiv.org/abs/1206.5743