Fondements de la nature

A l’Institut Paul Scherrer, les scientifiques cherchent des réponses à la question essentielle des structures élémentaires de la matière et des principes fondamentaux de fonctionnement dans la nature. Ils étudient la structure et les propriétés des particules élémentaires – les plus petits composants de la matière – ou se penchent sur la question de savoir comment les molécules biologiques sont structurées et remplissent leur fonction. Les connaissances qu’ils acquièrent de la sorte ouvrent de nouvelles pistes de solution en sciences, en médecine ou dans le domaine des technologies.

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Angle-resolved Photoemission (ARPES) on bilayer system La2-2xSr1+2xMn2O7

Bilayer manganites reveal polarons in the midst of a metallic breakdown

The origin of colossal magnetoresistance (CMR) in manganese oxides is among the most challenging problems in condensed- matter physics today. The true nature of the low-temperature electronic phase of these materials is heavily debated. By combining photoemission and tunnelling data, we show that in the archetypal bilayer system La2-2xSr1+2xMn2O7, polaronic degrees of freedom win out across the CMR region of the phase diagram.

Direct Observation of Local Mn-Mn Distances in the Paramagnetic Compound CsMnxMg1-xBr3

We introduce a novel method for local structure determination with a spatial resolution of the order of 0.01 Å. It can be applied to materials containing clusters of exchange-coupled magnetic atoms. We use neutron spectroscopy to probe the energies of the cluster excitations which are determined by the interatomic coupling strength J.

Dr. Nik Hauser and Prof. M. Stampanoni discuss results in the mammography room at Kantonsspital Baden. (PSI/M.Fischer)

Investigation of a new method for the diagnosis of cancer in breast tissue

Collaboration between research, hospital and industry aimed at transferring innovative procedure into daily practice.

Non-thermal melting of a charge density wave

We use time-resolved optical reflectivity and x-ray diffraction with femtosecond resolution to study the dynamics of the structural order parameter of the charge density wave phase in TiSe2. We find that the energy density required to melt the charge density wave nonthermally is substantially lower than that required for thermal suppression and is comparable to the charge density wave condensation energy.

PSI sets world record with 1.4 MW proton beam

The highest average power proton beam in the world was produced on 20th of June in the 590 MeV cyclotron at Paul Scherrer Institut. Extremely low beam losses achieved in this 35 years old veteran cyclotron allowed PSI team of accelerator scientists and engineers to put 1.4 MW beam of protons onto the muon and neutron spallation targets. This beam is used to produce the brightest beam of muons in the world, as well as supply neutrons for the spallation source SINQ.

Sketch of the orbital current (toroidal moment) within a CuO plaquette

Observation of Orbital Currents in CuO

Although high-temperature (Tc) superconductivity was discovered in the cuprates 25 years ago, there is still no consensus on its microscopic origin.

cross-section of the brain of a rat

X-ray methods help to understand brain disorders better

An international team of researchers from Denmark, Germany, Switzerland and France has developed a new method for making detailed X-ray images of brain tissue, which has been used to make the myelin sheaths of nerve fibres visible. Damage to these protective sheaths can lead to various disorders, such as multiple sclerosis. The facility for creating these images of the protective sheaths of nerve cells is being operated at the Swiss Light Source (SLS), at the Paul Scherrer Institute.

PSI scientists Valerio Scagnoli (left) and Urs Staub working on their experiment at SLS

The electron torus can help us to understand high-temperature superconductors

Paul Scherrer Institute researchers prove, for the first time, the existence of toroidal currents in solids

PSI-Feriencamp 2011

Suchen Sie für Ihr Kind ein spannendes Angebot während den Sommerferien? Möchten Sie in ihm die Neugier und Begeisterung für naturwissenschaftlich-technische Themen wecken? Die Berufsbildung und das Komitee für Chancengleichheit führt dieses Jahr zum achten Mal das PSI-Feriencamp durch!