Exact analytical expressions for the switching delay of an inverter driving an RC load, taking into account the velocity saturation, are obtained. Modified expressions to include theeffectofsource resistance arethen presented.Owing to the limitation on switching current imposed by the velocity saturation mechanism, the switching delay is substantially increased for identical width-io-length rat...

The dynamics of an electron in a one-dimensional superlattice is investigated under the action of a THz electric field. The density matrix equations of motion within a single miniband are solved using a relaxationtime approximation for scattering. The electronic response to THz radiation is obtained by calculating the dipole moment, whence we compute the power dissipated, the THz reflection coe...

We have studied doped superlattices of GaAs/AlGaAs composition. When the doping atoms are introduced into the barriers surrounding the superlattice, as well as to the inner ones, but with half of the concentration, the photoluminescence due to interband transitions from extended superlattice states is detected. This is demonstrated by a study of the sample’s photoluminescence in a magnetic fiel...

Coherent coupling and formation of molecular orbitals in vertically coupled quantum-dot molecules is studied for a seven-dot InAs/GaAs system. The electron states are computed using a nanoelectronic modelling tool NEMO-3D. The tool optimizes atomic positions in the sample with up to 64 million atoms in the frame of the atomistic VFF model. The resulting optimal interatomic distances are then us...

We report on the observation of coherent electronic wave-packet oscillations in a semiconductor heterostructure at room temperature. Bloch oscillations are excited in a wide-miniband GaAs/Al0.3GaO.7As superlattice by femtosecond laser pulses. Several cycles of the coherent electronic motion are observed within the dephasing time of the intraband polarization. The frequency can be tuned by the a...