The characteristics of terahertz (THz) irradiation generated by a silicon nanosandwich structure under the conditions of a stabilized drain-source current are demonstrated. The frequency of irradiation arising from the quantum Faraday effect is determined by the parameters of microcavities embedded in the edge channels of a silicon nanosandwich structure confined by the negative-U centers. The obtained characteristics of a compact THz irradiation source determine the basis for highly effective medical applications.
Self-organization mechanisms promoting elimination of cracks in thick GaN layers grown on sapphire substrates are considered on the basis of the experimental results on the fabrication of the layers by Hydride Vapor-Phase Epitaxy on MOCVD-grown GaN/Al2O3 templates. The obtained data support the supposition on the closure of tensile stress-related cracks via diffusion processes and demonstrate the strong contribution of bulk diffusion in addition to surface diffusion discussed earlier.
It is shown that a single-walled carbon nanotube based on a carbon monolayer (graphene) rolled up into a cylinder is a nanoscale quantum system characterized by the presence of electron crystals, like graphene. In contrast to the extremely unstable graphene quantum system, the nanotube quantum system is stable at a certain curvature of the carbon skeleton. The curvature causes the redistribution of π electrons between internal and external electron crystals accompanied by the formation of...