Attosecond XUV Four Wave Mixing in Solids
Abstract
Four wave mixing is universally used to probe short time dynamics in solids, liquids, and gases. The methodology provides important new information about time evolving processes that are typically invisible to basic pump-probe methods, such as couplings that are obscured by heterogeneous broadening. The beginnings of four wave mixing work with extreme ultraviolet pulses (XUV) are just becoming available at powerful free electron lasers. However, table top attosecond four wave mixing using weak attosecond XUV pulses combined with strong visible optical pulses has found great success in gases in the principal investigator s laboratory. In this program it is proposed to merge two strong visible optical pulses with one weak attosecond extreme ultraviolet pulse in solid state materials to produce new emissions of a fourth XUV pulse. Two arrangements will be developed, (1) using the XUV attosecond pulse first, and probing by suitably time-delayed visible optical pulses in a noncollinear configuration, and (2) forming a transient grating of carriers with two visible optical pulses first, impinging at an angle, followed by probing the grating with the XUV attosecond pulse. The XUV spectral range has several powerful characteristics: the ability to detect element specific core level transitions, so the experiments adopt the viewpoint of each element in the sample, sensitivity to oxidation state and bond length changes, resulting in accessibility to signatures of electrons and holes, as well as phonon motions. Examples of the science to be pursued in solids are the diffusion of carriers in materials formed by transient gratings, coherent electronic and phonon motions and the correlations between electron temperatures and phonon excursions, measurement of core level exciton lifetimes, assignment and detection of dark state core level exciton states, and probing of charge density wave order in solids.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 12, 2021
- Source ID
- FA95502010334
Entities
People
- Stephen R. Leone
Organizations
- Air Force Office of Scientific Research
- United States Air Force
- University of California Regents