July 11, 2018
- Associate Professor David J. Flannigan is a guest co-editor, with Aaron M. Lindenberg from Stanford University, for an issue of MRS Bulletin titled "Ultrafast Imaging of Materials Dynamics," which appeared on July 10, 2018. The articles in the issue represent a cross section of the vigorous activity occurring in the study of light-induced ultrafast materials dynamics as it relates to charge carriers, surfaces and interfaces, lattice-coupling mechanisms, coherent structural motions, and next-generation instrument development. As discussed in the Introductory Article by Flannigan and Lindenberg, the highlighted approaches are providing a wealth of new physical insights, leading to new possibilities for engineering the properties of matter, and ultimately, producing a new understanding and perspective of materials functionality on ultrasmall and ultrashort spatiotemporal scales.
The figure above from the Flannigan research group shows an ultrafast electron-imaging snapshot of directional, nanoscale hypersonic strain waves in undoped, single-crystal Ge. The select false-colored image of the strain-wave motion reveals the material response 315 picoseconds after excitation with a femtosecond laser pulse and was acquired with an effective exposure time of less than one picosecond. The dot-dashed line marks the position of a single wavefront, while the dotted line marks the center position, which is used to monitor the overall relative position during hypersonic propagation. In so doing, they were able to image the waves traveling at up to 35 nanometers per picosecond, which is nearly 80,000 miles per hour.
Related Link: https://www.cambridge.org/core/journals/mrs-bulletin/issue/ultrafast-imaging-of-materials-dynamics/438DCF7802590C43E42D695C60E9F981