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BRIGHT & VISIONARY CUIIns Ights Into the hamb NEWSUrg Centre for Ultrafast ImagIng English Issue • Summer 2015 ExcEllEnt REsEaRch ULTRAFAST DYNAMICS WOMEN AS ROLE MODELS NWE Professors How do particles move Mildred Dresselhaus Award Hamburg offers excellent and why do we want has long lasting effects on research and career to know? career and co-operations opportunities Pages 2-13 Page 16 Pages 20 -23 R ESEARCH Dear reader! The illustration (left) from the absorption edges of individual chemical elements Jens S. Kienitz (CFEL, DESY) within the molecule. We are very pleased to present to you shows the alignment of molecu- the first English issue of our CUI News as les with light. A strong laser field Moreover, static and dynamic electrical fields can be a compact version of the previous four (red) forces randomly oriented used to align the molecules in space (Fig. 1). This is especial- German issues. A lot has happened since free molecules into a preferred ly important for the investigation of chemical reactions our cluster of excellence got started on direction (Fig. 1). which almost always depend on the relative alignment of 1 November 2012. Colleagues from Uni- the reaction partner involved. For the excitation, detection versität Hamburg, DESY, the Max Planck Illustration (below) on the inves- and orientation of molecules, short light pulses are needed Institute for the Structure and Dynamics tigation of superfluidity carried not only in the visible and ultraviolet but also in the X-ray of Matter, the European XFEL GmbH, and out by the group headed by Pro- and terahertz spectral range. Therefore, the scientists use the European Molecular Biology Labora- fessor Henning Moritz and Pro- the state-of-the-art X-ray radiation sources available in tory have been working together to solve fessor Ludwig Mathey (Universi- Hamburg, such as the electron storage ring PETRA III and some of the greatest and most exciting tät Hamburg): With a laser beam the free-electron laser FLASH at DESY and, before long, the challenges of contemporary science: (red) a cloud of ultra-cold atoms free-electron laser European XFEL. Simultaneously, new laser Observing and understanding the ultra- (blue) is stirred circularly, similar sources are being developed with an extended frequency fast dynamics of atoms, molecules and to a spoon in a mug of coffee. In range, shorter pulse duration and improved synchronization electrons, so that maybe, one day, we will this process it is shown that the (see article about spin-off, p. 6). Equally as important as the be able to control them systematically. cloud of atoms flows around the improvement of the optical sources is the further impro- By now, half of the project phase is moving obstacle without friction vement of the theoretical tools. These enable a more and over, and we are happy to say that the and – unlike coffee – is not set more realistic modelling and precise prediction of time-de- members of CUI have achieved excel- into rotation (Fig. 2). pendent quantum physics phenomena. lent results. These, among others, are represented in a long list of publicati- Even extended solids show certain macroscopic pheno- ons on our webpage mena which can only be explained by quantum physics. www.cui.uni-hamburg.de/en. In A prominent example is superconductivity. It is interpreted addition, the two and a half years were as a sophisticated interaction between paired electrons marked by exciting pioneering work: and their surrounding solid state lattice. Common materi- Appointing six new professors, building als become superconductive only at very low temperatures up new working groups, equipping A research report from research area A – and this still limits large-scale technical applications to new laboratories, and developing new „Imaging and CONTROL OF Quantum SYSTEMS“ a great extent. Hence, there is a major interest in de- methods. Looking at all the excellent veloping new materials offering a loss-free electric results, we are convinced that we have conduction at room temperature. With intensive set a good course for the research in our light fields, it is already possible, at field and that we will continue doing so. Quantum physics illustrates least for short periods of time, to make materials superconductive We received great news when we were FUNDAMENTAL processes even at room temperature. told that the German excellence initiati- ve will be continued after 2017. In parallel OF nature Because of the quantum nature with the political developments, the of superconductivity, it is very dif- members of CUI are discussing the ficult to simulate this phenome- future of our cluster. We are looking for- non with classical computers. At ward to a next excellence initiative and trictly speaking, all objects in the universe are “quantum systems”. tum gases can then be this point, the ultra-cold quan- we will apply with a new concept that Ultimately, all natural processes obey the laws of quantum physics. highly excited by the tum gases come into play again. we are currently developing. Although many larger systems can often be described in a classical way absorption of thousands The ultra-cold atoms are trapped In this issue of our CUI News we would Swhich is not based on quantum theory, research area A particularly focuses of photons as well. After this excitation, in a three-dimensional periodic force like to give you an overview of the three on the phenomena beyond classical physics. The scientists of this research a collaborative team in the CUI investiga- field shaped by superimposed light research areas including possible appli- area want to make fundamental processes of nature observable, display tes if and how the system, on a time-scale of fields, forming a solid state lattice. cations. Moreover, you will find what their development with time resolution and gain control over these systems micro- to milliseconds, finds its way back into its This creates a “quantum simula- international PhD students think about with the help of light. original BEC-state. tor” which allows one to repro- life in Hamburg and why scientists duce the behavior of real materi- returned from abroad to become a Representatives of these quantum systems are single atoms. The electrons Another interest of this research area concentrates als. Since such a simulator can be professor at CUI. We also asked our first of these atoms move on clearly defined paths – or more correctly quantum- on molecules: In molecules, the dynamics of electron perfectly controlled, it is ideally Mildred Dresselhaus Awardee to reflect mechanically– on clearly defined orbitals. Their dynamic changes are made movement is still linked to the – slower – movement suited for studying on the impact the prize has on her ca- visible particularly by their interaction with light. When irradiating the of atomic nuclei. Here, the goal is to track the change the influence of different parameters on Y - B R reer. Last but not least we are very proud atoms with X-ray light, the enormous intensity provided by free-electron of chemical bonds in real-time, i.e. with the necessary the investigated quantum phenome- R -14 A that our school lab keeps succeeding in lasers makes it possible that a single atom absorbs many photons within a time-resolution of 10 seconds, finding methods to non, free of interference. I very short time. At the same time, many electrons are knocked out of the control molecular processes with the help of light fields. N developing new projects to excite young G atomic shell, followed by a complicated cascade of subsequent processes. For this purpose, the molecules are again put into an A macroscopic quantum pheno- people about natural sciences. O H I The observation of these processes provides information on the interaction electronically excited state with laser pulses within a very menon which is closely related to T S Enjoy reading! I - of elementary quantum particles – the electrons – in the force field of a short period of time. The scientists of the research area superconductivity is superfluidity: A Prof. Dr. Klaus Sengstock highly-charged ion. have invented new methods of excitation. For example, fluid under certain circumstances does V Prof. Dr. Horst Weller the solvent bath is heated within picoseconds by using not offer any resistance to an object Prof. Dr. R. J. Dwayne Miller Research, however, does not only focus on single atoms. With appropriate terahertz pulses. The time-delayed detection of an exci- which is stirred in it. CUI scientists were CUI spokespersons cooling, many (one million or more) atoms can form a joint macroscopic ted transition state with X-ray pulses allows for a high able to show that this kind of superfluidity could also be quantum state, a “Bose-Einstein condensate (BEC)”. These ultra cold quan- chemical selectivity because it makes it possible to select realized in ultra cold quantum gases (Fig. 2). ■ 2 CUI News / English Issue, Summer 2015 I BRIGHT & VISIONARY BRIGHT & VISIONARY I CUI News / English Issue, Summer 2015 3 R ESEARCH / Application What is different in the United states? impact on information and consumer industries very clearly Prof. Hemmerich: In Germany, in the past ten years, we shows the strong influence of technology-related research re- have witnessed the increasing importance of collaborative sults. However, there is another very important aspect. In the project funding. The idea is that large project collaborations field of basic research, many young people get an extremely with an interdisciplinary and a thematically coordinated good professional training. They are in the midst of activities profile carry out the best research. In both countries, Ger- when something completely new is developed – there is no Professor Andreas Hemmerich emphasi- many and the United States, collaborative project funding better training.

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