Lab News & Scientific Highlights

Charge density wave (CDW) orders in vanadium-based kagome metals have recently received tremendous attention, yet their origin remains a topic of debate. The discovery of ScV₆Sn₆, a bilayer kagome metal featuring an intriguing √3 × √3 × √3 CDW order, offers a novel platform to explore the underlying mechanism behind the unconventional CDW. Here we combine ...

Spin–orbit coupling in noncentrosymmetric crystals leads to spin–momentum locking – a directional relationship between an electron’s spin angular momentum and its linear momentum. Isotropic orthogonal Rashba spin–momentum locking has been studied for decades, while its counterpart, isotropic parallel Weyl spin–momentum locking has remained elusive in experiments. Theory predicts ...

PSI hosted again the Hercules School in March 2022. We had the pleasure to welcome 20 international PhD students, PostDocs and scientists to demonstrate our state-of-the-art techniques and methodologies at our large scale facilities, the Swiss Light Source (SLS), the Swiss Spallation Neutron Source (SINQ) and our free electron laser SwissFEL.

The first endstation at the SwissFEL Athos soft X-ray branch is rapidly developing and on track for first experiments in 2021.

An international collaboration consisting of metrology and photon diagnostics groups Germany, the U.S.A., Switzerland, and Japan performed a set of cross-calibration measurements of optical properties on the Bernina branch of the Aramis beamline [1].  The collaboration saw the DESY-developed gas detector, a novel diamond detector from Brookhaven, and a room temperature radiometer from AIST in Japan placed at the Bernina end station and measure the absolute intensity of the FEL light as it passed through the optical elements.  The cross-calibrated measurements used in conjuction with the photon beam intensity-gas (PBIG) monitor at the front end of the Aramis beamline to characterize the performance of the optical components on the Bernina branch and then compare them to the expected theoretical values.  The measurements were performed at photon energies of 6.08 and about 7.22 keV.

The high brilliance of new X-ray sources such as X-ray Free Electron Laser opens the way to non-linear spectroscopies. These techniques can probe ultrafast matter dynamics that would otherwise be inaccessible. One of these techniques, Transient Grating, involves the creation of a transient excitation grating by crossing X-ray beams on the sample. Scientists at PSI have realized a demonstration of such crossing by using an innovative approach well suited for the hard X-ray regime.

In March 2018, the nine-week MOOC “Introduction to synchrotrons and x-ray free-electron lasers” (abbreviated to “SYNCHROTRONx”) came online via the edX provider of the École Polytechnique Fédérale de Lausanne (EPFL), created by Phil Willmott of the Swiss Light Source, Paul Scherrer Institute. “MOOC” is an acronym for “massive open online course”, a teaching platform started in the first decade of this century, which has become increasingly popular in the last five to six years. MOOCs have no limits to participation and are free. Some of the most popular MOOCs can attract many tens of thousands of participants. Even the most specialized subjects may have an initial enrollment of over a thousand, more than an order of magnitude larger than that typically found in traditional higher education. There were over 70 million MOOC enrollments covering nearly 10’000 subjects offered by the top five providers in 2017 alone!

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.

The team of the Laboratory for Advanced Photonics (LAP) has succeeded to perform the first set of shot-to-shot measurements of the SwissFEL generated spectrum.

On the 17th of December 2017 SwissFEL saw its first pilot experiment in the Alvra experimental station of the SwissFEL ARAMIS beamline.

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.