arXiv subjects

B. Mendez

Publications and source records attributed to B. Mendez.

3 recordsLinked to original sources

arXiv1995

FIBONACCI SUPERLATTICES OF NARROW-GAP III-V SEMICONDUCTORS

We report theoretical electronic structure of Fibonacci superlattices of narrow-gap III-V semiconductors. Electron dynamics is accurately described within the envelope-function approximation in a two-band model. Quasiperiodicity is introduced by considering two different III-V semiconductor layers and arranging them according to the Fibonacci series along the growth direction. The resulting energy spectrum is then found by solving exactly the corresponding effective-mass (Dirac-like) wave equation using tranfer-matrix techniques. We find that a self-similar electronic spectrum can be seen in the band structure. Electronic transport properties of samples are also studied and related to the degree of spatial localization of electronic envelope-functions via Landauer resistance and Lyapunov coefficient. As a working example, we consider type II InAs/GaSb superlattices and discuss in detail our results in this system.

cond-mat↗

arXiv1994

Electronic Structure of Fibonacci Si Delta-Doped Gaas

We study the electronic structure of a new type of Fibonacci superlattice based on Si $δ$-doped GaAs. Assuming that $δ$-doped layers are equally spaced, quasiperiodicity is introduced by selecting two different donor concentrations and arranging them according to the Fibonacci series along the growth direction. The one-electron potential due to $δ$-doping is obtained by means of the Thomas-Fermi approach. The resulting energy spectrum is then found by solving the corresponding effective-mass wave equation. We find that a self-similar spectrum can be seen in the band structure. Electronic transport properties of samples are also discussed and related to the degree of spatial localization of electronic envelope-functions.

cond-mat↗

arXiv1994

Exact Solutions of Two-Band Models of Graded-Gap Superlattices

We have theoretically investigated two-band models of graded-gap superlattices within the envelope-function approximation. Assuming that the gap varies linearly with spatial coordinate, we are able to find exact solutions of the corresponding Dirac-like equation describing the conduction- and valence-band envelope-functions. The dispersion relation inside allowed miniband of the superlattice may be expressed in terms of confluent hypergeometric functions in a closed form.

cond-mat↗