The metal centres in metalloenzymes and molecular catalysts are responsible for the
rearrangement of atoms and electrons during complex chemical reactions, and they enable …

Over more than a century, X-rays have transformed our understanding of the fundamental
structure of matter and have been an indispensable tool for chemistry, physics, biology …

In ultrafast spectroscopy, the temporal resolution of time-resolved experiments depends on
the duration of the pump and probe pulses, and on the control and characterization of their …

The cavity-based X-ray free-electron laser (XFEL) has promise in producing fully coherent
pulses with a bandwidth of a few meV and very stable intensity, whereas the currently …

Attosecond pulses are central to the investigation of valence-and core-electron dynamics on
their natural timescales,–. The reproducible generation and characterization of attosecond …

We demonstrate the generation of extreme-ultraviolet (XUV) free-electron laser (FEL) pulses
with time-dependent polarization. To achieve polarization modulation on a femtosecond …

Photoinduced isomerization reactions lie at the heart of many chemical processes in nature.
The mechanisms of such reactions are determined by a delicate interplay of coupled …

Free-electron lasers producing ultrashort pulses with high peak power promise to extend
ultrafast non-linear spectroscopic techniques into the extreme-ultraviolet–X-ray regime. Key …

It is a long-standing challenge for laser technologies to generate intense fully coherent
pulses in the x-ray regime. Here, we demonstrate an external seeding mechanism, termed …

Quantum entanglement between the degrees of freedom encountered in the classical world
is challenging to observe due to the surrounding environment. To elucidate this issue, we …