A Boltzmann Approach to Transient Bloch Emission from Semiconductor Superlattices
Résumé
Using the Boltzmann transport equation, we have analyzed the transient terahertz waveforms emitted from electrons undergoing Bloch oscillations in a semiconductor superlattice excited by femtosecond optical pulses. A good agreement between theory and experiment is obtained with fitting parameters that lead to a non-zero current at the initial time. This indicates that pulsed interband optical excitation cannot be interpreted as creating an initial electron population near the bottom of the one-dimensional electron minibands.