Time-Dependent Dielectric Functions for GaAs and Si Subjected to Intense Laser Pulses.
Abstract
Motivated by the experiments of Glezer et al.(<A HREF=http://mazur-www.harvard.edu>E.N. Glezer, Y. Siegal, L. Huang, and E. Mazur</A>, Phys. Rev. B 51), 6959 (1995). and Sokolowski-Tinten et al.(K. Sokolowski-Tinten, J. Bialkowski, and D. von der Linde, Phys. Rev. B 51), 14186 (1995). , we have performed simulations of the electron-ion dynamics of GaAs and Si subjected to intense laser pulses. For GaAs, the photon energy was taken to be 1.9 eV, the pulse width to be 70 femtoseconds , and the fluence to vary over the range of 0.0 to 2.5 kJ/m^2 . For Si, the corresponding quantities were 2.0 eV, 80 fs, and 0.0 to 3.5 kJ/m^2. In the present simulations, the imaginary part of the dielectric function ɛ(ω) is calculated from the available joint density of states, as electrons are excited to the conduction band and structural modifications are induced. As Im [ɛ(ω)] is monitored , during and after the application of the laser radiation, features are seen which provide a signature of band-gap collapse and metallic behavior. This work was supported by the Robert A. Welch Foundation.
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1997
- Bibcode:
- 1997APS..MAR.S2711G