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We put forward a mechanism for the current-induced spin polarization in semiconductor heterostructures, which is based on the complex structure of the valence band. It takes place for a light hole in a quantum dot side-coupled to a quantum wire with heavy holes. In stark contrast with the traditional mechanisms based on the linear in momentum spin–orbit coupling, an exponentially small bias applied to this structure is enough to create the 100% spin polarization in the quantum dot. Microscopically, this effect is related to the formation of the chiral quasi bound states and the spin-dependent tunneling of holes from the quantum wire to the quantum dot. This new concept is equally valid for the GaAs-, Si- and Ge-based nanostructures.

Fascinating optical properties governed by extremely confined excitons have been so far observed in 2D crystals like monolayers of transition metal dichalcogenides. These materials, however, are limited for production by epitaxial methods. Besides, they are not suitable for the development of optoelectronics for the challenging deep-ultraviolet spectral range. Here, we present a single monolayer of GaN in AlN as a heterostructure fabricated by molecular beam epitaxy, which provides extreme 2D confinement of excitons, being ideally suited for light generation in the deep-ultraviolet. Optical studies in the samples, supplemented by a group-theory analysis and first-principle calculations, make evident a giant enhancement of the splitting between the dark and bright excitons due to short-range electron–hole exchange interaction that is a fingerprint of the strongly confined excitons. The practical significance of our results is in the observation of the internal quantum yield of the room-temperature excitonic emission as high as ∼75% at 235 nm.

This paper presents the results of a study of the mechanisms of femtosecond laser interactions with a system of nanoparticles deposited on a solid insulating surface. Experiments showed that, depending on the intensity, various interaction regimes of the laser radiation with the nanoparticles are implemented, including partial and total separation (ablation) of the nanoparticles and local damage of the surface itself. In the regime of total and partial ablation of the nanoparticles, traces are recorded showing that ions of the material of the nanoparticles are incorporated in a thin near-surface layer of the substrate. Modelling the breakdown of nanoparticles by a femtosecond laser pulse confirms that it is possible for ions to be emitted from them, with subsequent incorporation in the substrate.

This paper presents the results of an analytical calculation and numerical modeling of the disintegration of a nanoparticle of a condensed medium partially ionized by a powerful ultrashort pulse (USP) of laser radiation. The mechanism of the process by which the nanoparticle is disintegrated by the Coulomb forces that result from the disruption of charge equilibrium in it under the action of the USP is established by comparing the results obtained by analytical and numerical methods. The kinetics of the energy spectrum of the dispersing ions is analyzed, taking into account the deceleration of the ions in the nanoparticle.

This paper presents the results of a model investigation of the consequences of total ionization of a nanoparticle of a condensed medium under the action of a powerful ultrashort pulse of laser radiation. Analytical and numerical methods are used to investigate the evolution of the spatial and energy distributions of ions of the medium in the course of their dispersal for various particle sizes and geometries.

The creation of new principles for the development of near-field probes in the last ten years has become a key aspect for the technological progress of near-field optics. The use of surface polaritons provides a new approach to the solution of this problem. Electromagnetic waves of this type can ensure not only an efficient energy channel along a near-field probe, but also good localization of the field at the end of the probe. © 2004 Optical Society of America

The theory of spin noise in low-dimensional systems and bulk semiconductors is reviewed. Spin noise is usually detected by optical means continuously measuring the rotation angle of the polarization direction of a probe beam passing through a sample. Spin noise spectra yield rich information about the spin properties of the system, for example, g-factors of the charge carriers, spin relaxation times, parameters of the hyperfine interaction, spin-orbit coupling constants, frequencies and widths of the optical resonances. The review describes basic models of spin noise, methods to theoretically describe it, and their relation to experimental results. We also discuss the relation between spin noise spectroscopy and strong and weak quantum measurements, as well as spin flip Raman scattering, and analyze similar effects, including manifestations of the charge, current, and valley polarization fluctuations in the optical response. Possible directions for further development of spin noise spectroscopy are outlined.

This paper discusses the localization processes of optical radiation when surface electromagnetic waves (SEWs) are excited in ordered arrays of scattering inhomogeneities whose size is much less than the wavelength of light. The features of the SEW excitation when ultrashort laser pulses act on the surface of a semiconductor are also investigated. The possibility of spatial and temporal localization of optical radiation in an SEW is analyzed.