Ultrafast optical control of ferroelectricity using intense terahertz fields has attracted significant interest. Here we show that the nonlinear interactions between two optical phonons in SnTe, a two-dimensional in-plane ferroelectric material, enables a dynamical amplification of the electric polarization within subpicoseconds time domain. Our first principles time dependent simulations show that the infrared-active out-of-plane phonon mode, pumped to nonlinear regimes, spontaneously generates in-plane motions, leading to rectified oscillations in the in-plane electric polarization. We suggest that this dynamical control of ferroelectric material, by nonlinear phonon excitation, can be utilized to achieve ultrafast control of the photovoltaic or other non-linear optical responses.
@article{arxiv.2010.13646,
title = {Nonlinear phononics in 2D SnTe: a ferroelectric material with phonon dynamical amplification of electric polarization},
author = {Dongbin Shin and Shunsuke A. Sato and Hannes Hübener and Umberto De Giovannini and Noejung Park and Angel Rubio},
journal= {arXiv preprint arXiv:2010.13646},
year = {2021}
}