Accession Number : ADA619937


Title :   Attosecond Electron Processes in Materials: Excitons, Plasmons, and Charge Dynamics


Descriptive Note : Final rept. 1 May 2014-30 Apr 2015


Corporate Author : CALIFORNIA UNIV REGENTS BERKELEY


Personal Author(s) : Leone, Stephen R


Full Text : https://apps.dtic.mil/dtic/tr/fulltext/u2/a619937.pdf


Report Date : 19 May 2015


Pagination or Media Count : 24


Abstract : A five year program focusing on investigation of attosecond electron dynamics in solid state materials is completed. Two experimental apparatuses for attosecond time-resolved extreme ultraviolet (XUV) studies were constructed. Highlights of results are: a 450 attosecond electronic response time in the conduction band of silicon was experimentally measured by observing steps in the L2,3-edge spectrum of silicon, synchronized with the excitation laser electric field. Independent electron and hole dynamics were observed in germanium by time-resolved ultrafast measurements on the M4,5-edge spectrum of germanium. A near-instantaneous spectral response over a broad range around the vanadium M2,3-edge, followed by a fast reshaping of the spectrum, was observed in VO2, suggesting a signature of the ultrafast insulator to metal transition.


Descriptors :   *CHARGE CARRIERS , *ELECTRON TRANSPORT , *EXCITATION , *EXCITONS , *PHASE TRANSFORMATIONS , *PLASMONS , ABSORPTION SPECTRA , CONDUCTION BANDS , DYNAMICS , ELECTRIC CHARGE , ELECTRIC FIELDS , FAR ULTRAVIOLET RADIATION , GERMANIUM , HOLES(ELECTRON DEFICIENCIES) , LASERS , NANOPARTICLES , SILICON , SPECTROSCOPY , THIN FILMS , VANADIUM


Subject Categories : Physical Chemistry
      Electricity and Magnetism
      Atomic and Molecular Physics and Spectroscopy
      Nuclear Physics & Elementary Particle Physics
      Solid State Physics


Distribution Statement : APPROVED FOR PUBLIC RELEASE