Controlling ultrafast currents by the nonlinear photogalvanic effect

Wachter, G. and Sato, S. A. and Floss, I. and Lemell, C. and Tong, X. M. and Burgdörfer, Joachim (2015) Controlling ultrafast currents by the nonlinear photogalvanic effect. NEW JOURNAL OF PHYSICS, 17. ISSN 1367-2630

Preview

Text 1503.06146.pdf Available under License Creative Commons Attribution. Download (479kB) | Preview

Abstract

We theoretically investigate the effect of broken inversion symmetry on the generation and con- trol of ultrafast currents in a transparent dielectric (SiO2) by strong femto-second optical laser pulses. Ab-initio simulations based on time-dependent density functional theory predict ultrafast DC currents that can be viewed as a non-linear photogalvanic effect. Most surprisingly, the direc- tion of the current undergoes a sudden reversal above a critical threshold value of laser intensity Ic ∼ 3.8 × 1013 W/cm2. We trace this switching to the transition from non-linear polarization cur- rents to the tunneling excitation regime. We demonstrate control of the ultrafast currents by the time delay between two laser pulses. We find the ultrafast current control by the non-linear pho- togalvanic effect to be remarkably robust and insensitive to laser-pulse shape and carrier-envelope phase.

Actions (login required)

Edit Item