Electronic and Structural Modifications of GaAs by Intense Laser Pulses
Abstract
Glezer et al. [1] have argued from their experimental results that GaAs undergoes a band gap collapse and structural deformation when subjected to an intense femtosecond laser pulse. We have performed simulations of the electron-ion dynamics of this system, using a tight-binding Hamiltonian. The interaction of the radiation field with the material is treated through a time-dependent Peierls substitution, which introduces no additional tight-binding parameters. The time-dependent Schroedinger equation is solved with an adapted Cayley algorithm which conserves probability. The atomic forces are determined by a generalized Hellmann-Feynman theorem which is valid for nonadiabatic processes. We find a variety of interesting phenomena, including a confirmation of the picture of Ref. 1: With the same intensities etc. employed in the experiment, there is indeed disruption of the lattice and band-gap collapse. This work was supported by the Office of Naval Research and Robert A. Welch Foundation. [1] E.N. Glezer, Y. Siegal, L. Huang, and E. Mazur, Phys. Rev. B 51, 6959 ( 1995).
- Publication:
-
APS March Meeting Abstracts
- Pub Date:
- March 1996
- Bibcode:
- 1996APS..MAR.K1507G