Analysis and control of electron dynamics, the birth of atto-magnetism and the predictive power of time-dependent DFT

by E.K.U. Gross

The Hebrew University Of Jerusalem

at Physics Colloquium

Mon, 14 Dec 2020, 16:00
Zoom: https://us02web.zoom.us/j/82307626973

Abstract

This lecture is about the motion of electrons on the femto- and atto-second time scale; how it can be monitored, analyzed and, ultimately, controlled with ultra-short laser pulses. Real-time simulations are performed employing the ab-initio approach of time-dependent density functional theory (TDDFT) as theoretical tool. We shall visualize the laser-induced formation and breaking of chemical bonds in real time, and we shall highlight non-steady-state features of the electronic current through nano-scale junctions. With the goal of pushing magnetic storage processes towards faster and faster time scales, we have predicted that in many materials the local magnetic moment can be manipulated with ultrafast laser pulses on the femto- and even atto-second time scale. The underlying mechanism is an optically induced spin transfer (OISTR) from one magnetic sub-lattice to another. As an all-optical process, OISTR is temporally limited by the duration of the laser pulse. OISTR was first predicted by TDDFT calculations and two years later found experimentally. The OISTR effect marks the birth of “atto-magnetism”.

Zoom link: https://us02web.zoom.us/j/82307626973

Created on 07-12-2020 by Kats, Yevgeny (katsye)
Updaded on 07-12-2020 by Kats, Yevgeny (katsye)