Control and Imaging of processes triggered by X-ray pulses in multi-center molecules

Attoscience is one of the great scientific challenges of the 21st century. While femtosecond laser pulses provided a candid camera into the world of nuclear motion, attosecond laser pulses will bring a revolution in our understanding of electron dynamics. Attoseconds and sub-femtoseconds are the natural time scale for multi-electron effects during complete ionization and break-up of atoms and molecules.
Attosecond ``steering" of electrons in chemical bonds using ultra-short pulses is a fundamental way of manipulating
the molecular structure. Controlling the electronic motion in small molecules will pave the way for modifying
the structure of complex biomolecules, thus impacting such diverse fields as physics, chemistry and biology.


The overall aim of the proposed work is to harness the properties of ultra-short and ultra-strong laser pulses to time-resolve and control attosecond phenomena triggered by intense X-ray laser pulses in multi-center molecular systems. The rapid experimental advances make urgent the quest for new theoretical tools that will address the challenges facing Attoscience.
The main intellectual weapon that I bring is my expertise on novel, non-mainstream quasiclassical techniques that are much faster than quantum-mechanical ones and that allow for significant insights into the physical mechanisms. These techniques are appropriate for ionization processes through long range Coulomb forces. I propose to deliver sophisticated and efficient techniques for tackling some of the most fundamental problems facing Attoscience. My objectives are:

1)Explore the correlated dynamics of two-electron escape during the break-up of multi-center molecules triggered by intense and ultra-fast X-ray pulses.
2)Explore pump-probe schemes for coherent control and transfer of electrons in multi-center molecules.
3)Use infrared laser pulses as an ``attosecond clock" to accurately map the properties of the observed spectra of the final fragments to the temporal evolution of correlated electron escape dynamics during the break-up, by X-rays, of molecules.

The proposed research is on exploring multi-electron effects on an attosecond time-scale during the complete ionization
and break-up of multi-center molecules. Understanding the electronic motion on an attosecond time-scale in atomic and
molecular systems will be of importance in the future for a number of industries that closely work with applied researchers in order to enhance the industries' capabilities.
My results will be communicated to these applied researchers through academic dissemination but most importantly through direct interaction with them at the London Center for Nanotechnology (LCN). LCN aims to provide the nanoscience and nanotechnology needed to solve major problems in information processing, health care, and energy and environment.
In the sense mentioned above, my research will contribute in addressing the first two of the above strategic areas of LCN---such potential applications of attoscience are well-acknowledged and identified.

Namely, the density of information flow, such as operations performed by a computer, is determined by how fast the electron current can be switched on and off in a digital chip.
The current state-of-the-art in electronic circuits dictates a switching time within a fraction of a nanosecond. To achieve higher density of information, faster switching times need to be achieved, such as attoseconds. The latter is the natural time-scale for electronic motion in neighbouring atoms in a crystal lattice or in a small molecule. Thus, understanding and controlling the attosecond electronic
motion in molecules (one of the goals of the proposed research) and solid state structures opens up the way for researching technologies that may lead to speeding up current electronics
by several orders of magnitude. In addition, controlling the electronic motion in small molecules using ultrashort laser pulses (one of the goals of the proposed research) will pave the way for ``steering" electronic motion and thus affecting the structure of biomolecules. This will lead to a better understanding of how to control radiation damage in biological systems and thus how to achieve the best effect in radiation therapies, significantly impacting the technology associated with health care.