Wurtzite nanowires strain control by DC electrical stimulation

Nanomechanics is a highly developed area of research, given the significant reported changes in material properties at the nanometer scale, requiring the development of new theories to explain the underlying mechanisms. Such theories must be based on measurements that are as accurate as possible, but unfortunately, conventional experimental techniques do not apply to such small components. Here we present a unique new method to control electro-mechanical forces on quasi −1D nanostructures through static electric fields with multiple ways of control of GaAs nanowires’ strain directly on the growth substrate

Spin-orbit interaction in three-dimensionally bounded semiconductor nanostructures

The structural inversion asymmetry-induced spin-orbit interaction of conduction band electrons in zinc-blende and wurtzite semiconductor structures is analysed allowing for a three-dimensional (3D) character of the external electric field and variation of the chemical composition. The interaction, taking into account all remote bands perturbatively, is presented with two contributions: a heterointerface term and a term caused by the external electric field. They have generally comparable strength and can be written in a unified manner only for 2D systems, where they can partially cancel each other. For quantum wires and dots composed of wurtzite semiconductors new terms appear, absent in zinc-blende structures, which acquire the standard Rashba form in 2D systems.Comment: 18 pages, 1 figur

Erratum to: 36th International Symposium on Intensive Care and Emergency Medicine

[This corrects the article DOI: 10.1186/s13054-016-1208-6.]

Model of a GaAs quantum dot embedded in a polymorph AlGaAs nanowire

International audienceWe report on a numerical model of quasi onedimensional and quasi zero-dimensional semiconductor heterostructures. This model is strictly based on experimental structures of cylindrical nanocolumns of AlGaAs grown by molecular-beam epitaxy in the (111) direction. The nanocolumns are of 20 - 50 nm in diameter and 0.5 - 1 ìm in length and contain a single GaAs quantum dot, of 2 nm in thickness and 15 - 45 nm in diameter. Since the crystal phase of these nanowires spontaneously switches during the growth from zincblende (Zb) to wurzite (Wz) structures we implement a continuum elastic model and 8 band ~k * ~p model for polymorph crystal structures. The model is used to compute electromechanical fields, wavefunction energies of the confined states and optical transitions. The model compares a pure Zb structure with a polymorph in which the Zb disk of GaAs is surrounded by Wz barriers and results are compared to experimental photoluminescence excitation spectra. The good agreement found between theory and features in the spectra supports the polyphorm model