electron

Phonon-plasmon coupling in electron surface accumulation layers in InN nanocolumns

Raman measurements in high quality InN nanocolumns display a coupled LO phonon-plasmon mode together with uncoupled phonons. The coupled mode is attributed to the spontaneous accumulation of electrons on the lateral surfaces of the nanocolumns. For …

Electronic energy levels of quantum well wires

An efficient variational method to solve the two‐dimensional Schrödinger equation using a basis set of cubic $B$ splines is introduced. The method, which uses the effective mass theory and the envelope function approximation, is applied to find the …

Local origin of photocurrent in semiconductor superlattices

To trace the origin of photocurrent (PC) in semiconductor superlatices, we have studied the PC spectra as a function of the applied electric field in a novel compositionally graded superlattice, where each well produces a separate peak. The sample …

Change in dimensionality of superlattice excitons induced by an electric field

We have observed an electric-field-induced change in the dimensionality of excitons in superlattices, from three to quasi-two dimensions. The exciton binding energy of a (40 Å/(40 Å) GaAs/(GaAl)As superlattice, determined from low-temperature …

Coherence and localization in semiconductor superlattices under electric fields

Using optical techniques, we have demonstrated that the quantum coherence of electron states in GaAs/GaAlAs superlattices under electric fields increases drastically as the period, $D$, and the electric field, $\cal{E}$, decrease, reaching at least …

Interactions between extended and localized states in superlattices

We have observed electric-field-induced interactions between the extended states of a (40 Å)-(15 Å) GaAs-Ga0.65Al0.35As superlattice and the localized state of an 80-Å terminating GaAs well. At fields such that the energy of an extended state was …