2016/02/17 by Grübel, S., Johnson, J. A., Beaud, P. +14
#FOS: Physical sciences #Materials Science (cond-mat.mtrl-sci)
paper · doi:10.48550/arxiv.1602.05435
Intense, few-cycle pulses in the terahertz frequency range have strong potential for schemes of control over vibrational modes in solid-state materials in the electronic ground-state. Here we report an experiment using single cycle terahertz pulses to directly excite lattice vibrations in the ferroelectric material Sn2P2S6 and ultrafast x-ray diffraction to quantify the resulting structural dynamics. A model of a damped harmonic oscillator driven by the transient electric field of the terahertz pulses describes well the movement of the Sn2+ ion along the ferroelectric soft mode. Finally, we describe an anharmonic extension of this model which predicts coherent switching of domains at peak THz-frequency fields of 790 kV/cm.