Dresden 2011 – scientific programme

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A: Fachverband Atomphysik

A 28: Attosecond physics II

A 28.1: Invited Talk

Wednesday, March 16, 2011, 10:30–11:00, BAR 205

Quantum Interference Control of Free and Bound Electrons in Atoms and Molecules — •Thomas Pfeifer — Max-Planck Institut für Kernphysik, Saupfercheckweg 1, 69117 Heidelberg

Electrons are the fundamental building blocks of molecular and condensed-phase bonds and the motion of electrons (migration, localization, ionization, etc.) governs the course of chemical reactions and defines molecular potential-energy landscapes. In the valence shell of atoms and molecules, electron dynamics typically proceeds on few-femtosecond and faster time scales, such that extremely short pulses and controlled light electric fields are needed to measure and to control these scientifically relevant quantum-electronic processes.

In this talk, we shall discuss experiments and the physical description of electronic quantum control. It will be shown that by using very short light pulses with a stabilized carrier-envelope phase (CEP) – and thus a fully controlled temporal electric field evolution – it is possible to steer the process of ionization and electron localization in atoms and molecules.

Most importantly, we can identify the mechanisms of this type of control as fundamental scenarios of quantum control among energetically degenerate states. As theoretically established by Brumer and Shapiro a long time ago, quantum interference among different light-induced transition pathways in atoms and molecules is at the heart of electronic control experiments. The intuitive physical pictures arising from this traditional understanding of electronic control in combination with the possibilities opened up by modern CEP-stabilized laser light electric fields and attosecond pulses paves the way towards more comprehensive applications of electronic control in more complex systems.