Ultra-Fast Dynamics Imaging

Hi, my name is Camilo Ruiz and i am special correspondent sent to the island of Ischia close to Naples Italy for the conference Ultra-Fast Dynamics Imaging celebrated from 30/04 - 03/05 in 2009.

This small workshop was organized by the local group at University of Naples and many of the most important players in the attosecond science were invited to participate. While attosecond is all about precious stability only achieved in well equipped and rich labs, everybody was happy to be invited to the southest part of Europe, where the sun is always there and there is not much of a rush, so we had a perfect combination.



The full program of the conference as well as the book of abstract can be found in the conference web page , i will instead point out some of the topics that i liked more together with some references.

On wednesday 29th, we had several good results. From the University of Frankfurt, Reinhard Dörner presented a paper on "Inteference and electron entanglement in photoionization of H2 and N2", this work is published in Science recently and explore the question of electron localization: When a diatomic molecule absorb a big photon a hole is produce because a k-shell electron is ionized, but then the question is weather the hole created is localized or not. In the case of the hole being localized, the electron hole should hope in 20 fs, later in time an Auger electron should be emitted to fill the hole. If this electron is emitted from one electron only, it should be diffracted but if it is not localized, probably the diffraction will be vanished.

Quotimg the reference: "Whether the core hole is better thought of as being localized or delocalized depends on the direction in which the photoelectron or Auger electron is emitted. Detecting the direction of the photoelectron in the experiment selects between cases in which the transient core hole is best described by a delocalized state of g or u symmetry, and other cases for which it is more appropriate to think of a localized hole. This situation can be described by a coherent superposition of gerade and ungerade states, or alternatively by a superposition of states corresponding to a hole on the left and one on the right."

Certainly there is more to it, as the enviroment breaks this description, but as expected the answer is very quantum like. These are beautiful experiments which don't even need a fast pulse, these are synchrton radiation only. Will time might play a role? Lets find a 419 eV photons in a short pulse to answer that.

The gropu of Garching talked about the new set of experiments in solid interfaces, these are very interesting results, more interesting is the new rout of this leading lab which will concentrate on multiple streaking. As this is something i am also doing i will not mention anything more about it. But try this paper.

These are just two talks, so you can imagine the number of things happening. The next message might be about the new XFELs around the globe.