Wannier-Mott excitons formed by electrons in a quantum wire and holes in a perpendicular quantum layer

We analyze Wannier-Mott excitons in which the electrons are constrained in one-dimensional quantum wires and the holes in two-dimensional quantum layers perpendicular to the wires. The resulting three-dimensional exciton Schrodinger equation in the laboratory frame of reference is solved in terms of the common 3D exciton states in the center of mass frame. (C) 2002 Elsevier Science B.V. All rights reserved

Transit times for electromagnetic waves in metallic layered systems

Metallic multilayered arrays are considered, in the local Drude theory, to investigate transit times of electromagnetic waves and the fast response mediated by plasmon polaritons. The transit times are calculated for frequencies corresponding to band gaps in the dispersion relation of periodic layered media. At these frequencies, and depending on the thickness of the structure, a fast response or even a superluminal effect is predicted. This effect is more evident near the plasmon polariton resonances. Moreover, the time delay is also affected by the surface plasmon coupling between the metallic layers. The metallic superlattices are described according to the Drude theory. (C) 2000 Published by Elsevier Science B.V. All rights reserved

Solution to the excitonic problem of an electron in a quantum wire and a hole in a perpendicular 2D quantum layer

We calculate the states of an exciton formed by an electron confined in a ID quantum wire (QW) and a hole confined in a 2D quantum layer (QL) perpendicular to the QW. The effective potential can be exactly calculated in the particular case where the confinement thicknesses are the same for the QW and QL. This effective potential can be used to calculate the exciton states for arbitrary confinement thicknesses, but here we show that in the limit of vanishing thickness the solution of our equation is very similar to the 3D bulk exciton equations, and therefore we can use these 3D exciton solutions as a basis for our system in a quantum perturbative approach

Bulk anisotropic excitons in type-II semiconductors built with 1D and 2D low-dimensional structures

We used a simple variational approach to account for the difference in the electron and hole effective masses in Wannier-Mott excitons in type-II semiconducting heterostructures in which the electron is constrained in an one-dimensional quantum wire (1DQW) and the hole is in a two-dimensional quantum layer (2DQL) perpendicular to the wire or viceversa. The resulting Schrodinger equation is similar to that of a 3D bulk exciton because the number of free (nonconfined) variables is thre