Low Temperature Physics: 29, 165 (2003); https://doi.org/10.1063/1.1542437 (9 pages)
Физика Низких Температур: Том 29, Выпуск 3 (Март 2003), c. 225-236 ( к оглавлению , назад )
Particle transport phenomena in low temperature solids
M. Bargheer and N. Schwentner
Institut für Experimentalphysik, Freie Universität Berlin Arnimallee 14, 14195 Berlin, Germany
Received November 11, 2002
We review different approaches to measure the transport of F atoms and ions in rare gas matrices and compare the experimental results to simulations. Static measurements on sandwich structures and co-doped matrices yield rather long travel ranges beyond 2 nm, in accord with early classical simulations which predict a channeling of the F atoms in rare gas matrices. Nonadiabatic simulations show a rapid energy loss, fast nonadiabatic dynamics and only short travel ranges of typically
1 unit cell. The rapid energy loss, fast nonadiabatic transitions and the timescale for direct dissociation (~ 250 fs) are verified by fs-pump-probe experiments. It remains a challenge to account for the long-range migration when nonadiabatic processes are allowed in simulations, and to measure the long distance flights directly by ultrafast spectroscopy.