References and Notes

These results demonstrate the ability of present-day ultrashort-laser–driven x-ray sources to study transiently generated ex-treme states of matter. Although further stud-ies of important outstanding problems related to the structure of superheated solids and transient liquid phases (1, 2) are natural ex-tensions of this work, foreseeable improve-ments already in development in tabletop la-ser-driven plasma sources should expand the scope of ultrafast x-ray diffraction to the dynamic study of many other ultrafast pro-cesses in physics, chemistry, and biology, including the ultrafast atomic and molecular dynamics by which other solid-state process-es and chemical and biochemical reactions take place