Scientists report the first look at electrons moving in real-time in liquid water; findings open up a whole new field of experimental physics.
In an experiment akin to stop-motion photography, scientists have isolated the energetic movement of an electron while “freezing” the motion of the much larger
From the Nobel Prize to the field
Subatomic particles move so fast that capturing their actions requires a probe capable of measuring time in attoseconds, a time frame so small that there are more attoseconds in a second than there have been seconds in the history of the universe.
The current investigation builds upon the new science of attosecond physics, recognized with the 2023 Nobel Prize in Physics. Attosecond X-ray pulses are only available in a handful of specialized facilities worldwide. This research team conducted their experimental work at the Linac Coherent Light Source (LCLS), located at SLAC National Accelerator Laboratory, in Menlo Park, California, where the local team pioneered the development of attosecond X-ray free-electron lasers.
“Attosecond time-resolved experiments are one of the flagship R&D developments at the Linac Coherent Light Source,” said Ago Marinelli from the SLAC National Accelerator Laboratory, who, together with James Cryan, led the development of the synchronized pair of X-ray attosecond pump/probe pulses that this experiment used. “It’s exciting to see these developments being applied to new kinds of experiments and taking attosecond science into new directions.”
The technique developed in this study, all X-ray attosecond transient absorption spectroscopy in liquids, allowed them to “watch” electrons energized by X-rays as they move into an excited state, all before the bulkier atomic nucleus has time to move. They chose the liquid water as their test case for an experiment.
“We now have a tool where, in principle, you can follow the movement of electrons and see newly ionized molecules as they’re formed in real-time,” said Young, who is also a professor in the Department of Physics and James Franck Institute at the DOI: 10.1126/science.adn6059
The study has three co-first authors: S. Li, Lu, and Swarnendu Bhattacharyya of DESY. The three corresponding authors are X. Li, Santra and Young.
This work was primarily supported by IDREAM, an Energy Frontier Research Center funded by the Department of Energy, Office of Science, Basic Energy Sciences program. Use of the LCLS, the SLAC National Accelerator Laboratory, and resources from the Center for Nanoscale Materials, Argonne National Laboratory, are supported by the DOE Office of Science, Basic Energy Sciences program. Additional support came from DESY and Cluster of Excellence, “CUI: Advanced Imaging of Matter,” of the Deutsche Forschungsgemeinschaft.