Carl Ramsauer Award 2008 for two former PhD students of the Max Born Institute
11. November 2008

Dr. Claus Ropers (31) and Dr. Anke B. Schmidt (31) are two of the winners of this year’s Carl-Ramsauer prize of the Berlin Physical Society. Claus Ropers did his doctor degree at the Humboldt University and Anke Schmidt is awarded for her doctoral thesis at the Free University. They did their research work at the Max Born Institute for Nonlinear Optics and Short Pulse Spectroscopy. The prize will be awarded on the 19th of November.
More (in german) ...

Hydrogen bonds: Scientists find new mechanism

Water’s unrivalled omnipresence and the crucial role it plays in life drives scientists to understand every detail of the processes underlying waters unusual properties on a molecular level. Bernd Winter and his colleagues from the Max Born Institute (MBI) and the Berlin Electron Storage Ring for Synchrotron-Radiation (BESSY) have now been able to study a hitherto unknown property of the negatively charged hydroxide ion (OH-) of water. They report about this in the prestigious science magazine Nature (E.F. Aziz, N. Ottosson, M. Faubel, I.V. Hertel, und Winter, B., Nature, 455, 89-91,2008)

The crystal strikes back

The dashing start of electrons in a crystal does not remain without consequences for their further fate. This is reported by the Berlin researchers Peter Gaal, Wilhelm Kuehn, Klaus Reimann, Michael Woerner and Thomas Elsaesser of the Max Born Institute and Rudolf Hey of the Paul Drude Institute in the latest issue of the magazine Nature (Vol. 450, Page 1210). They examined the ultrafast movement of electrons in a gallium arsenide crystal exposed for a short time to a very high electrical field. This conceptually new experiment shows for the first time a collective, oscillatory motion of the electrons with ultrahigh frequency, which arises additionally to the well-known drift motion of these particles. This newly discovered effect could play an important role in connection with the miniaturization of electronic devices.
More information: Project 3-02,  Press release of AlphaGalileo

Molecular Pirouettes - Researchers in Berlin and Munich watch closely molecules as they reorient themselves during ultrafast photochemical reactions

Ultrafast intramolecular electronic charge separation during photo-chemical reactions cause up to tenthousand surrounding molecules to perform aligning pirouettes. Researchers observed for the first time such light induced reorientations in an organic molecular crystal. Scientists of the Max-Born-Institute for Nonlinear Optics and Ultrafast Spectroscopy and of the Ludwig-Maximilians-University in Munich report their recent experimental results in the current issue of the journal Physical Review Letters (vol. 98, page 248301).
In their study they initiated a separation of positive and negative electronic charge in a small number of particular molecules with extremely short light pulses. In turn the surrounding molecules responded by aligning their respective dipole axes along the photoinduced electric fields. The researchers observed this fundamental process for the first time by means of femtosecond x-ray diffraction with high spatial precision and in real time.
More information: Project 3-04

Nature features two recent MBI publications

Recent publications from the MBI on aqueous proton transfer and on ultrashort spatially confined electron pulses have been featured in the News and Views section of Nature magazine.
In the 15 March 2007 issue, James T. Hynes highlights recent work on the base-induced solvent switch model for aqueous proton transfer. More information: see contribution in News and Views of Nature, the original publication in Angewandte Chemie International Edition and our own project pages.
In the 29 March 2007 issue, Herman Batelaan and Kees Uiterwaal discuss recent work on the generation of femtosecond electron pulses from nanoscale metal tips. More information: see contribution in News and Views of Nature, the original publication in Physical Review Letters and our own project pages.

Cover Picture ChemPhysChem 5/2007: Excited-State Relaxation of Protonated Adenine

The MBI has a strong tradition investigating dynamic processes in isolated chromophores. Dirk Nolting and coworkers now extended such time-resolved investigations to protonated biomolecules. For the DNA base adenine, an accelerated internal conversion from electronic to nuclear energy was observed. Such fast processes may prevent potentially destructive photochemical processes.
The cover picture shows the potential energy scheme of protonated adenine. The adenine molecule in front is in the ground-state equilibrium geometry whereas the molecule in the back shows the nonplanar structure after absorption of an UV photon. In their Article on page 751 Nolting et al. investigate the excited state dynamics of protonated adenine by femtosecond pump-probe transient mass spectrometry in the gas phase.
More information: ChemPhysChem (April 2, 2007)

Electron flashes for the nanoworld – a new source of ultrashort electron pulses

Researchers at the MBI have presented a novel source of extremely short electron pulses. The electron source is based on an ultra-sharp metallic needle illuminated with ultrashort laser pulses. The particular excitation conditions result in an extremely short duration of the electron pulses of less than 0.02 picoseconds (20 femtoseconds) which allows for studying ultrafast processes in nanosystems.
More information: C. Ropers et al., Physical Review Letters, Vol. 98, 043907 (2007), press release.

The external evaluation of the MBI has been finished. The assessment is excellent.

On Nov. 23, 2006 the senate of the Leibniz Association recommended to continue the funding without limitations for the next 7 years. The senate emphasizes that the MBI belongs to the worldwide leading institutes in the field of nonlinear optics and ultrafast dynamics of the interaction of light and matter.
Press release of the Leibniz Association, press release of the Forschungsverbund Berlin e.V.

"J. Phys. B's 2006 Highlights", chosen by the Editorial Board of Journal of Physics B

Two of the 24 highlights of the year 2006 are publications that emerged from the project 2-02.

Topical Review: "Above-threshold ionization by few-cycle pulses", D. B. Milosevic, G. G. Paulus, D. Bauer, and W. Becker, J. Phys. B 39, R203-262 (2006)
The term Above-Threshold Ionization (ATI) refers to the features of the angle-resolved electron spectrum of atoms ionized by an intense laser pulse. For the past 25 years, this effect has been instrumental for understanding the interaction of an intense laser pulse with an atom. Recently, due the availability of laser pulses of only a few cycles' duration with controlled temporal evolution (stable carrier-envelope phase), ATI has revealed many more fascinating facets.
Letter to the Editors: "Attosecond electron thermalization by laser-driven electron recollision in atoms", X. Liu, C. Figueira de Morisson Faria, W. Becker, and P. B. Corkum, J. Phys. B 39, L305-311 (2006)
The paper investigates electron recollision as the mechanism of nonsequential multiple ionization of atoms. A very simple, almost analytically solvable, statistical model is introduced, which turns out to describe very well the data produced by the Heidelberg group for triple and quadruple ionization of neon [K. Zrost et al., J. Phys. B 39, 40 (2006)]. The model assumes a delay between the time of the recollion and the later time when the electrons are blown off, which is on the attosecond time scale.

Fund ranking of the Deutsche Forschungsgemeinschaft (DFG)

The MBI achieved an excellent position in the most recent ranking of funding through the Deutsche Forschungsgemeinschaft (DFG). Acquiring funding from the DFG is considered one of the key indicators for excellent research in Germany. The report mainly focusses on the universities but also lists about 170 non-university research institutions in Germany. On this list, the MBI holds position 16. Also, the MBI is one of the very few non-university institutions specifically mentioned for good networking with universities. This aspect becomes even more evident from the DFG-maps on networking in physics and in chemistry.

Klaus Tschira Award 2006 for former MBI Ph.D. student

Dr. Nils Huse has received the Klaus Tschira Award for 2006 for his tutorial presentation of research results on "The short memory of water". In his contribution he describes how with modern methods of experimental physics one can investigate the anomalies of water. The award ceremony took place on 12th October 2006 at the University of Heidelberg. More information: see contribution in Bild der Wissenschaft Plus (in German) and project pages.

Lise-Meitner Award 2006 for former MBI Ph.D. student

Dr. Nils Huse has received the Lise-Meitner Award 2006 of the Freunde und Förderer der Physik der HU Berlin and the Institut für Physik at the Humboldt Universität zu Berlin for his dissertation "Multidimensional Vibrational Spectroscopy of Hydrogen-Bonded Systems in the Liquid Phase Coupling Mechanisms and Structural Dynamics". The award ceremony took place on 20th July 2006 at the Humboldt Universität zu Berlin. More information: see press release (in German) and project pages.

Walter Schottky Award 2006 of the German Physical Society (DPG) for Heisenberg scholar

Dr. Manfred Fiebig and his colleagues at MBI demonstrated for the first time that electric and magnetic properties of multiferroics are correlated and that magnetic structures of multiferroics may be purposefully controlled by applying electric fields.
More information: see press release (in German)

One of "J. Phys. B's 2005 Highlights", chosen by the Editorial Board of Journal of Physics B
"Strong laser field ionization of Kr: first-order relativistic effects defeat rescattering"

E Gubbini, U Eichmann, M Kalashnikov and W Sandner, Max-Born-Institute Berlin

The magnetic component of a light wave is, in most cases, negligible compared to the electric one. This changes in ultra-strong laser fields, where electrons may be ionized and acclererated to relativistic speeds. Trajectory deviations of the order of a few atomic diameters, caused by magnetic light forces, have been measured with great precision in the present experiment.
J. Phys. B: At. Mol. Opt. Phys. 38 No 6 (28 March 2005) L87-L93
More information: see Project 2-02

Carl-Ramsauer-Award 2005 for former MBI student

Dr. Helmut Lippert has received the Carl-Ramsauer-Award 2005 of the Physical Society in Berlin for his dissertation "Ultra short spectroscopy of isolated and micro-solvated biochromophors". The award ceremony took place on 16th November 2005 at the university of Potsdam.
More information: see press release (in German)

Scientific highlight from a collaboration between the MBI and the Ben Gurion University of the Negev published in SCIENCE Volume 310 of 7 October 2005, p. 83-86.

Mohammed et al. report on a sequential, von Grotthuss-type, proton hopping mechanism through water bridges in aqueous acid-carboxylic base reactions.
More information: see Breaking news in Projekt 2-04

Scientific highlights from a collaboration between the MBI and the University of Toronto published in NATURE Volume 434, Number 7030, Issue of 10 March 2005.

Cowan et al. (p. 199) demonstrate that the fastest hydrogen bond fluctuations in neat liquid water (H2O) occur on a sub-50 femtosecond time scale, resulting in an extremely fast loss of structural memory. This has been revealed by multi-dimensional vibrational spectroscopy of the O-H stretching vibration of water.
More information: see Highlights in 2005

Nano-Motion Pictures: One goal of ultrafast x-ray structural studies is to image atomic motions in materials in a nondestructive manner. Bargheer et al. (p. 1771) imaged coherent atomic motions in a GaAs/AlGaAs superlattice that were induced by exciting electron-hole pairs in the GaAs subband. This excitation process weakens the bonding in the GaAs layers, which causes them to expand and the AlGaAs layers to contract. From their analysis of the small changes they observed in weak reflections, the authors argue that the layers cycle between expansion and contraction every 3.5 picoseconds and launch coherent acoustic standing waves.