DVDs and Blu-ray disks contain so-called phase-change materials that morph from one atomic state to another after being struck with pulses of laser light, with data “recorded” in those two atomic states.
Using ultrafast laser pulses that speed up the data recording process, researchers adopted a novel technique, ultrafast electron crystallography (UEC), to visualize directly in four dimensions the changing atomic configurations of the materials undergoing the phase changes.
In doing so, they discovered a previously unknown intermediate atomic state—one that may represent an unavoidable limit to data recording speeds.
