Biomedical subjects

G J Salamo

Publications and source records attributed to G J Salamo.

4 recordsLinked to original sources

PubMed2006

Electric-field-induced domain evolution in ferroelectric ultrathin films.

The electric-field-induced evolution of the recently discovered periodic 180 degree nanostripe domain structure is predicted in epitaxial Pb(Zr0.5Ti0.5)O3 ultrathin films from first principles. This evolution involves (1) the lateral growth of majority dipole domains at the expense of minority domains with the overall stripe periodicity remaining unchanged, (2) the creation of surface-avoiding nanobubbles, and (3) the formation of a single monodomain state. Analogies and differences (i) with ferroelectric thin films made of BaTiO3 and (ii) with ferromagnetic thin films under magnetic field are discussed.

Journal Article↗

PubMed2006

Controlling planar and vertical ordering in three-dimensional (In,Ga)As quantum dot lattices by GaAs surface orientation.

Anisotropic surface diffusion and strain are used to explain the formation of three-dimensional (In,Ga)As quantum dot lattices. The diffusion characteristics of the surface, coupled with the elastic anisotropy of the matrix, provides an excellent opportunity to influence the dot positions. In particular, quantum dots that are laterally organized into long chains or chessboard two-dimensional arrays vertically organized with strict vertical ordering or vertical ordering that is inclined to the sample surface normal are accurately predicted and observed.

Journal Article↗

PubMed2005

Photoluminescence intermittency of InGaAs/GaAs quantum dots confined in a planar microcavity.

Photoluminescence intermittency, or "blinking", was observed in semiconductor InGaAs/GaAs quantum dots (QDs) inside a planar microcavity. Most of the blinking QDs were found around defect sites such as dislocation lines naturally formed in the GaAs barrier layers, and the carrier traps responsible for blinking had an excitation threshold of approximately 1.53 eV. The blinking properties of epitaxial QDs and colloidal nanocrystal QDs were also compared by performing laser intensity dependent measurements and statistics of the "on" and "off" time distributions.

Journal Article↗

PubMed2001

Spatially resolved spin-injection probability for gallium arsenide.

We report a large spin-polarized current injection from a ferromagnetic metal into a nonferromagnetic semiconductor, at a temperature of 100 Kelvin. The modification of the spin-injection process by a nanoscale step edge was observed. On flat gallium arsenide [GaAs(110)] terraces, the injection efficiency was 92%, whereas in a 10-nanometer-wide region around a [111]-oriented step the injection efficiency is reduced by a factor of 6. Alternatively, the spin-relaxation lifetime was reduced by a factor of 12. This reduction is associated with the metallic nature of the step edge. This study advances the realization of using both the charge and spin of the electron in future semiconductor devices.

Journal Article↗