The dynamic evolution of spatially inhomogeneous electronic excitations coupled to a phonon reservoir is investigated on ultrashort time scales. For this purpose, the in-plane propagation of an optically excited electron-hole density profile is studied in an idealized semiconductor quantum well with equal electron and hole masses. Assuming low density and excitation pulses localized on a micron scale, it is shown that the optically induced electron transport exhibits a crossover from ballistic to diffusive motion depending on the details of the electron-phonon coupling.
ASJC Scopus subject areas
- Condensed Matter Physics