Condensed Matter

Painters and photographers depict the outer aspect of objects. In the past, objects had to be destroyed or taken apart in order to look inside them. Since Konrad Röntgen, we cannot only look inside the living person but we can also look through matter. Today, we are able to penetrate into the inside of many states of matter; and soon we will even be able to observe atoms during chemical reactions.

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The term "condensed matter" comprises a very large part of the states matter can take on: for example solid matter, fluids, biological materials, colloids, nanostructures, liquid crystals, polymers or glass. These substances exhibit a broad range of different effects, such as transparency, magnetism, superconductivity, viscosity, colours or texture of surfaces, or the way biological systems function. Huge time scales are also involved, ranging from some femtoseconds for electronic processes in solid matter to millions of years in geological processes. A broad range of scientific puzzles is studied using these complex many-particle systems in order to grasp the diverse states and properties of condensed matter. This constantly forces the researchers to develop new instruments and methods suited to the task at hand. Besides the fascinating challenges which arise for basic research, condensed matter physics also is the basis for a wide variety of applications, for example in the materials sciences, nanotechnology, geology, chemistry, the environmental sciences or structural biology.

In order to conduct cutting-edge research in this field, a first-class scientific infrastructure with a broad range of different instruments is mandatory. The vast majority is operated at universities, Max Planck Institutes and other research institutions. The BMBF is mainly responsible for the construction and operation of large-scale facilities demanding substantial effort and resources, such as research reactors, particle accelerators, and high-intensity lasers as a source of

Moreover, the BMBF supports cooperation of universities with research centers within the framework of Collaborative Research (Verbundforschung). This funding is intended specifically to develop new instrumentation and research methods.

Research institutions with BMBF participation

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Research with Neutrons

A characteristic of neutrons is that they pass through matter for the purpose of structural analyses without destroying it. Images from the inside of massive probes can thereby be gained; this would be very difficult or even impossible e.g. with X-rays. This applies in particular to metals or materials with a high density. This property of neutrons is used in many ways in science and applications, for example in detecting micro fissures in aircraft components, in analysing sewage sludge or in monitoring water and soil quality in environmental sciences. In medicine, examinations with neutrons were paramount in understanding how bones mineralize and, later, demineralize during growth.

Research with neutrons is therefore an indispensable method of analysis for many areas of science and technology. The intensity of radiation is of particular importance: The greater the intensity, the more precise measurements are in many cases. The intensity of a neutron source is therefore important to its significance for research.

Neutron sources are so-called research reactors, which generate neutrons by means of uranium fission. In the Federal Republic of Germany, large research reactors are operated in Berlin and Garching (near Munich). In 2006, the "Research Neutron Source Heinz Maier-Leibnitz (FRM II)" became operational, a reactor currently supplying second-highest neutron flux worldwide armed with most modern instrumentation. Furthermore, Germany participates in the high-flux reactor (ILL) in Grenoble and supports work on the research reactor at the Joint Institute for Nuclear Research (JINR ) in Dubna, Russia. The Research Centre Jülich (FZJ) is currently setting up a powerful neutron experiment at the most intense neutron spallation source worldwide, SNS in the USA.

As of 2010, Germany participates in the design and realization of the new European Spallation Source (ESS ) in Lund, Sweden. The BMBF is currently supporting a project conducted jointly with Helmholtz Research Centers and the Munich Technical University (TUM). Of the total of 21M€, 15M€ are contributed by the BMBF and 6M€ by the participating project partners.

  

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Research with Photons (Synchrotron Radiation)

Examining the inner structure of matter even in tiniest samples and observing changes even on shortest time scales is facilitated by modern accelerator-based light sources. The light produced there, called "synchrotron radiation", is part of the electromagnetic spectrum. More commonly known types of electromagnetic radiation include visible light, X-ray radiation or radio waves. Synchrotron radiation is much more intense than that of conventional X-ray sources. It is generated by means of particle accelerators, where not the particles themselves (electrons or positrons) are used, but the radiation they emit.

Synchrotron radiation is an extremely potent tool to study condensed matter, often complementary to neutrons. A vast range of materials, microscopic systems, phenomena and processes is accessible to this research, and, correspondingly, the experimental techniques are extraordinarily diverse.

Synchrotron radiation, which is simply the emission of energy in the form of electromagnetic radiation, is produced whenever electrically charged particles change direction. An example is the case of electrons at high energies in a circular accelerator, which are kept on their track using magnets. The radiation emitted in the arcs is used for synchrotron radiation experiments. Using special periodic magnet structures (wigglers or undulators), the electrons can even be forced on a slalom track, thus going through many small curves in sequence, which will amplify the radiative process. The light emitted in this case has special highly desirable properties: It is extremely intense and comes in narrowly focussed rays. If the undulators are long enough, rays generated by an electron at the different points in the undulator may overlap, which causes an additional amplification. The beam of light thus generated has properties of laser light (coherence) and is extremely bright.

Free-electron lasers carry this scheme even further by setting up accelerating structures and undulators in a straight line. This allows the rays emitted even from different electrons on their way through the undulator to overlap. When this happens, a coherent laser light beam of extremely well-defined energy is produced which also is extremely bright and comes in extremely short pulses with an enormous repetition rate. Because of these properties, it allows to sample the progress of processes occurring on on atomic lengths, in three dimensions: a movie of chemical reactions or molecular processes comes within reach.

FLASH, the first free-electron laser for wavelengths in the soft X-ray or VRV range, took up operation in 2005 at DESY, Hamburg. Since then, it is serving the user community. In 2010, construction of a much larger free-electron laser for hard X-ray radiation, the European XFEL , began, also in Hamburg. 

Large-scale Equipment and Research Centers

Synchrotron Radiation Sources:

• BESSY II, HZB Berlin 
• DORIS III, DESY Hamburg
• PETRA III, DESY Hamburg
• ANKA, KIT Karlsruhe 
• ESRF, Grenoble 
• SLS, Paul Scherrer Institut (PSI), Villigen 

Free-Electron Lasers:

• FLASH, DESY Hamburg 
• European XFEL, Hamburg 
• LCLS, Stanford, USA

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Research with particles carrying electric charge

With this method of structural analysis, radioactive nuclei, muons, positrons or ions are implanted into materials to probe the internal electromagnetic fields and forces. In addition to the areas of solid state physics and materials research, this research method is also used in the life sciences and the geosciences, in anthropology, medicine and art.

Large-scale Equipment and Research Centers

• Material research  at UNILAC, GSI
• ISOLDE, CERN 
• Positron source at FRM II, Garching
• Ionenstrahlzentrum HZDR

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High-intensity Laser

The bombardment of solid matter with high-intensity laser beams generates hot and dense plasmas in matter, similar, for example, to the conditions in the interior of Jupiter.

Large-scale Equipment and Research Centers

Max Born Institute (MBI), Berlin

• High-intensity laser

Helmholtz-Zentrum Gesellschaft für Schwerionenforschung, Darmstadt (GSI )

• Phelix: high-intensity laser facility