Light-pulse pairs reveal the femtosecond decay of an inner-shell hole in xenon atoms

Researchers at the UVSOR Synchrotron Facility (Institute for Molecular Science, Japan) and partner institutions have observed the decay of a xenon 4d core hole, an inner-shell vacancy, directly in the time domain. They used pairs of phase-coherent extreme ultraviolet pulses from a synchrotron to make the photoelectron wave packets they released interfere. The contrast of the interference fringes decreased over a few femtoseconds as the delay between the pulses increased. A model using literature core-hole lifetimes of about 6 femtoseconds reproduced this rapid decay of the fringe contrast. The study is published in the journal Physical Review A.