Matter and Material

“Higgs Particle Found” announced the media triumphantly in July 2012. But for Roland Horisberger, particle physicist at PSI, this was a premature conclusion: “It will take at least another five years before we can be sure of that”. Whatever the findings à whether this is the original Higgs boson, or only one of the theoretical “Higgs-like” particles à one can surely put a tag on them that reads “PSI inside.”

Muons à unstable elementary particles à provide scientists with important insights into the structure of matter. They provide information about processes in modern materials, about the properties of elementary particles and the nature of our physical world. Many muon experiments are only possible at the Paul Scherrer Institute because of the unique intense muon beams available here.

Scientists use nano-rods to investigate how matter assemblesTo make the magnetic interactions between the atoms visible, scientists at the Paul Scherrer Institute PSI have developed a special model system. It is so big that it can be easily observed under an X-ray microscope, and mimics the tiniest movements in Nature. The model: rings made from six nanoscale magnetic rods, whose north and south poles attract each other. At room temperature, the magnetisation direction of each of these tiny rods varies spontaneously. Scientists were able to observe the magnetic interactions between these active rods in real time. These research results were published on May 5 in the journal “Nature Physics”.

Forscher des PSI und der ETH Zürich haben mit Kollegen vom Politecnico di Milano in der aktuellen Ausgabe der wissenschaftlichen Fachzeitschrift "Nature Photonics" eine Methode erarbeitet, einen Laser zu entwickeln, der schon bald in den neuesten Computern eingesetzt werden könnte. Damit könnte die Geschwindigkeit, mit der einzelne Prozessorkerne im Chip miteinander kommunizieren, drastisch erhöht werden. So würde die Leistung der Rechner weiter steigen.This news release is only available in German.

Prominent among the planned applications of X-ray free electron laser facilities, such as the future SwissFEL at the Paul Scherrer Institute, PSI, are structural studies of complex nano-particles, down to the scale of individual bio-molecules. A major challenge for such investigations is the mathematical reconstruction of the particle form from the measured scattering data. Researchers at PSI have now demonstrated an optimized mathematical procedure for treating such data, which yields a dramatically improved single-particle structural resolution. The procedure was successfully tested at the Swiss Light Source synchrotron at PSI.

Developmental Engineers from the firm LuK (D) wanted to see right through the metal housing of a clutch. They wanted to observe how the oil that lubricates and cools a clutch is distributed. A transparent disc becomes dirty very quickly, and X-rays merely reveal the metal. These engineers therefore turned to scientists at the Paul Scherrer Institute, who illuminated the metal with neutrons and thus made the lubricating oil visible. The results surprised everyone: only three of the eight lamellae were sufficiently lubricated.

Scientists at the Paul Scherrer Institute, together with Chinese and German collaborators, have obtained new insights into a class of high-temperature superconductors. The experimental results of this fundamental research study indicate that magnetic interactions are of central importance in the phenomenon of high-temperature superconductivity. This knowledge could help to develop superconductors with enhanced technical properties in the future.

X-rays are used to investigate nanoscale structures of objects as varied as single cells or magnetic storage media. Yet, high-resolution images impose extreme constraints on both the X ray microscope and the samples under investigation. Researchers at the Technische Universität München the PSI now showed how to relax these conditions without loss of image quality. They further showed how to image objects featuring fast fluctuations, such as the rapid switching events that determine the life time of data storage in magnetic materials.

Researchers from the Paul Scherrer Institute and the Indian Institute of Science Education and Research have been able to intentionally ‘switch off’ the magnetization of every second molecule in an array of magnetized molecules and thereby create a ‘magnetic nano-chessboard’. To achieve this, they manipulated the quantum state of a part of the molecules in a specific way.

An international team of scientists confirmed the surprisingly small value of the proton radius with laser spectroscopy of exotic hydrogen. The experiments were carried out at PSI which is the only research institute in the world providing the necessary amount of muons for the production of the exotic hydrogen atoms made up of a muon and a proton.

Interview with Thomas HuthwelkerThe Paul Scherrer Institut makes its research facilities available to scientists from all over the world. To ensure these scientists are exposed to optimal conditions when they arrive is the hard work of many PSI staff. An interview with one of these scientists provides a glimpse behind the scenes. This interview is taken from the latest issue of the PSI Magazine Fenster zur Forschung

An international research team has determined with a high level of accuracy, how the proton participates in the weak interaction à one of the fundamental forces of nature. Their results confirm the predictions of the Standard Model of particle physics. The experiment observed the probability of muon capture by protons à a process governed by the weak interaction. The experiment was conducted at the Paul Scherrer Institute, the only institute in the world with an accelerator capable of generating enough muons for carrying out this project in a realistic timeframe.

Stretching a layer of silicon can lead to internal mechanical strain which can considerably improve the electronic properties of the material. Researchers at the Paul Scherrer Institute and the ETH Zurich have created a new process from a layer of silicon to fabricate extremely highly strained nanowires in a silicon substrate. The researchers report the highest-ever mechanical stress obtained in a material that can serve as the basis for electronic components. The long term goal aim is to produce high-performance and low-power transistors for microprocessors based on such wires.

Paul Scherrer Institute (PSI) researchers have investigated the mechanisms necessary for enabling the semiconductor Germanium to emit laser light. As a laser material, Germanium together with Silicon could form the basis for innovative computer chips in which information would be transferred partially in the form of light. This technology would revolutionise data streaming within chips and give a boost to the performance of electronics.

A new X-ray technique provides insights into the magnetic properties of atomically thin layers of a parent compound of a high-temperature superconductor. It turns out that the magnetic properties of material films which are only a few atoms thick differ by only a surprisingly small degree from those of macroscopically thick samples. In the future, this method can be used to study the processes occurring in very thin layers of superconductors and help us to understand this intriguing phenomenon.

In a joint seminar today at CERN and the ICHEP 2012 conference in Melbourne, researchers of the Compact Muon Solenoid (CMS) experiment at the Large Hadron Collider (LHC) presented their preliminary results on the search for the standard model (SM) Higgs boson in their data recorded up to June 2012.

How can two materials which do not conduct electricity create an electrically conducting layer when they are joined together? Since this effect was discovered in 2004, researchers have developed various hypotheses to answer this question. Now, an international team under the leadership of researchers at the Paul Scherrer Institute has probably settled the controversy.

An electron has been observed to decay into two separate parts, each carrying a particular property of the electron: a spinon carrying its spin à the property making the electron behave as a tiny compass needle à and an orbiton carrying its orbital moment à which arises from the electron’s motion around the nucleus. These newly created particles, however, cannot leave the material in which they have been produced.

Researchers at the Paul Scherrer Institute are finding out how long it takes to establish magnetism and how this happens. Establishing a magnetically ordered phase in the metallic alloy iron-rhodium takes much longer than the reverse process of demagnetization. The result comes from basic research, but has relevance for the computer industry, as it shows which processes limit the speed of magnetic data storage and where improvements might be made.

An international research team has demonstrated a new way to record information on a magnetic medium without the use of a magnetic field. Instead, they found that they could record information using only a heat pulse. This method of recording might allow one to record Terabytes (1000s of Gigabytes) of information per second being 100s of times faster than present hard drive technology, and consumes much less energy by using heat without the need for a magnetic field. Using modern lithographic methods and x-ray microscopy, researchers from the Paul Scherrer Institute contributed considerably to this work.