News & Scientific Highlights

This experiment performed at SwissFEL shows how fast we can localize electrons out of an electron gas into correlated, well localized states of a material. It is based on a combined ultrafast x-ray absorption and diffraction experiment on an intermetallic system.

FEL-based ultrafast calorimetry measurements show enhancement and maximum in the isobaric specific-heat.

Ultrafast long-range coherent dynamics in electronic structure excited by THz pulses and studied using free electron laser based resonant X-ray diffraction.

Organic–inorganic ‘hybrid’ perovskites have recently gained attention as a low-cost alternative to silicon solar cells. However, many properties of these materials are still poorly understood. In particular, how imperfections in the crystals, which can be both static or dynamic, affect energy transport remains unclear.

The summer shutdown was used to install more missing hardware. With the new components the Bernina instrument will be already very close to the full design capabilities when the exciting time of user experiments will begin in 2019.

X-ray Free Electron Lasers (XFELs) combine the properties of synchrotron radiation (short wavelengths) and laser radiation (high lateral coherence, ultrashort pulse durations). These outstanding machines allow to study ultra-fast phenomena at an atomic level with unprecedented temporal resolution for answering the most intriguing open questions in biology, chemistry and physics.

On the 30th of November 2017 SwissFEL saw its first time resolved pilot experiment in the Bernina experimental station of the SwissFEL ARAMIS beamline. A team of scientists from the University of Rennes, ESRF and PSI, led by Marco Cammarata (Univ. Rennes) and Henrik Lemke (PSI), successfully started the experimental phase at SwissFEL. The goal was to study the picosecond dynamics of a light-induced phase transition from a semiconductor to metallic crystal structure in a Titanium Oxide (D).

We employ time-resolved resonant x-ray diffraction to study the insulator-to-metal transition that is launched via resonant excitation of an infrared-active optical phonon mode in a half doped manganite. We find that the charge order reduces promptly with a highly nonlinear (quartic) dependence on excitation fluence.