Pairs of light waves can be used to observe and manipulate a single electron as it moves inside an atom — motion that happens on the timescale of one-millionth of one-billionth of a second.
Physicists have long been able to take portraits of individual atoms by firing a beam of electrons at a target. But tracking changes in the arrangement of an atom’s electrons is much more challenging, because such changes take so little time.
Tatsuo Kaneyasu at the SAGA Light Source in Tosu, Japan, and his colleagues have now observed such rapid changes in an atom of xenon gas. The scientists zapped the atom with pairs of ultrashort light pulses generated by a synchrotron, a type of particle accelerator. They then detected the electron movement induced by the interaction between the atom and the light pulses. They found that this movement could be controlled by precisely tuning the time between the two pulses.
The authors suggest that their approach could be used to explore and manipulate ultrafast electron motion for a wide range of elements.