A team of Physics World editors have sifted through research updates published on the website this year according to the following criteria: significant advance in knowledge or understanding, importance of work for scientific progress and/or development of real-world applications, and of general interest to Physics World readers.
Under the leadership of Jörg Evers' group from the Keitel division, the first experimental proof of coherent control of nuclear excitations by X-rays succeeded. A stability of the coherent control of a few zeptoseconds (thousandths of an attosecond) was achieved. In the experiment at the European Synchrotron ESRF, the researchers, including Christian Ott's group from the Pfeifer division, used two samples enriched with the iron isotope 57Fe, which were irradiated with short X-ray pulses from the synchrotron. With the first sample, they generated a controllable double X-ray pulse, which was then used to control the dynamics of the nuclei in the second sample.
In the framework of the BASE collaboration at CERN, Matthew Bohman in his PhD work in Klaus Blaum's division has successfully implemented a new method for cooling protons using laser-cooled ions – here beryllium ions. The special feature: In the new setup, the two types of particles are in spatially separated traps. An electric resonant circuit transfers the cooling power over a distance of several centimetres from one trap to the other. In this way, the proton in one of the traps can be cooled significantly more than without beryllium in the neighbouring trap. The method also works with antimatter, and the large distance also enables interference-free and precise measurements, e.g. in the search for dark matter with the help of antimatter.
Physics World announces its finalists for the 2021 Breakthrough of the Year
