Highlights

Coherent control of an atom by synchrotron radiation

Coherent control is a method to manipulate the populations and pathways in matters by light and is currently one of the most attractive research areas in optical physics and photochemistry. Lasers have been considered as unique light source enabling one to perform coherent control. However, in recent studies published in Nature Communications and Physical Review Letters, the research group that Prof. Masahiro Katoh (Hiroshima Univ.) directs has demonstrated an unremarked capability of synchrotron radiation on the coherent control. They employed devices called undulators, which was capable of producing synchrotron light pulses with tailored waveform. They shone He atoms with those pulses and demonstrated that the populations of the individual excited states of He atoms can be controlled. Moreover, they also demonstrated that the shape and orientation of the electron cloud surrounding the atomic nuclei can be controlled. There is no technical restriction on the application of this method at shorter wavelengths to which lasers could hardly reach soon. This unexploited capability of synchrotron radiation will advance the frontier of coherent-control technology.