Location Qubits in a Multiple-Quantum-Dot System.

A physical platform for nodes of the envisioned quantum Internet is long-sought. Here we propose such a platform, along with a conceptually simple and experimentally uncomplicated quantum information processing scheme, realized in a system of multiple crystal-phase quantum dots. We introduce novel location qubits, describe a method to construct a universal set of all-optical quantum gates, and simulate their performance in realistic structures, including decoherence sources.

Direct Band Gap AlGaAs Wurtzite Nanowires.

Wurtzite AlGaAs is a technologically promising yet unexplored material. Here we study it both experimentally and numerically. We develop a complete numerical model based on an 8-band method, including electromechanical fields, and calculate the optoelectronic properties of wurtzite AlGaAs nanowires with different Al content.

Purcell Effect and Beaming of Emission in Hybrid AlGaAs Nanowires with GaAs Quantum Dots.

Control of directionality of emissions is an important task for the realization of novel nanophotonic devices based on nanowires. Most of the existing approaches providing high directionality of the light emitted from nanowires are based on the utilization of the tapered shape of nanowires, serving as nanoantenna coupling with the light waveguided in nanowire and the directional output beam. Here we report the beaming of the emitted light with wavelength near 800 nm by naturally formed core-shell AlGaAs NW with multiply GaAs quantum dots (QDs) diameter 30 nm and height 10 nm, while the diameter of NW 130 nm, what does not support efficient emission into waveguided modes, including the mode HE.

All-optical charging and charge transport in quantum dots.

Optically active quantum dots are one of the promising candidates for fundamental building blocks in quantum technology. Many practical applications would comprise of multiple coupled quantum dots, each of which must be individually chargeable. However, the most advanced demonstrations are limited to devices with only a single dot, and individual charging has neither been demonstrated nor proposed for an array of optically active quantum dots.

Wurtzite AlGaAs Nanowires.

Semiconducting nanowires, unlike bulk, can be grown in both wurtzite and zincblende crystal phases. This unique feature allows for growth and investigation of technologically important and previously unexplored materials, such as wurtzite AlGaAs. Here we grow a series of wurtzite AlGaAs nanowires with Al content varying from 0.

Epsilon-Near-Zero Grids for On-chip Quantum Networks.

Realization of an on-chip quantum network is a major goal in the field of integrated quantum photonics. A typical network scalable on-chip demands optical integration of single photon sources, optical circuitry and detectors for routing and processing of quantum information. Current solutions either notoriously experience considerable decoherence or suffer from extended footprint dimensions limiting their on-chip scaling.

Nanowire Quantum Dots Tuned to Atomic Resonances.

Quantum dots tuned to atomic resonances represent an emerging field of hybrid quantum systems where the advantages of quantum dots and natural atoms can be combined. Embedding quantum dots in nanowires boosts these systems with a set of powerful possibilities, such as precise positioning of the emitters, excellent photon extraction efficiency and direct electrical contacting of quantum dots. Notably, nanowire structures can be grown on silicon substrates, allowing for a straightforward integration with silicon-based photonic devices.

Crystal Phase Quantum Well Emission with Digital Control.

One of the major challenges in the growth of quantum well and quantum dot heterostructures is the realization of atomically sharp interfaces. Nanowires provide a new opportunity to engineer the band structure as they facilitate the controlled switching of the crystal structure between the zinc-blende (ZB) and wurtzite (WZ) phases. Such a crystal phase switching results in the formation of crystal phase quantum wells (CPQWs) and quantum dots (CPQDs).

Photon Cascade from a Single Crystal Phase Nanowire Quantum Dot.

We report the first comprehensive experimental and theoretical study of the optical properties of single crystal phase quantum dots in InP nanowires. Crystal phase quantum dots are defined by a transition in the crystallographic lattice between zinc blende and wurtzite segments and therefore offer unprecedented potential to be controlled with atomic layer accuracy without random alloying. We show for the first time that crystal phase quantum dots are a source of pure single-photons and cascaded photon-pairs from type II transitions with excellent optical properties in terms of intensity and line width.

Growth and optical properties of axial hybrid III-V/silicon nanowires.

Hybrid silicon nanowires with an integrated light-emitting segment can significantly advance nanoelectronics and nanophotonics. They would combine transport and optical characteristics in a nanoscale device, which can operate in the fundamental single-electron and single-photon regime. III-V materials, such as direct bandgap gallium arsenide, are excellent candidates for such optical segments.

Bright single-photon sources in bottom-up tailored nanowires.

The ability to achieve near-unity light-extraction efficiency is necessary for a truly deterministic single-photon source. The most promising method to reach such high efficiencies is based on embedding single-photon emitters in tapered photonic waveguides defined by top-down etching techniques. However, light-extraction efficiencies in current top-down approaches are limited by fabrication imperfections and etching-induced defects.

[Regulatory influence of hippocampus CA1 and CA3 areas on bulbar respiratory neurons under hypoxia].

We studied the influence of stimulation of the CA1 and CA3 areas of the hippocampus on the impulse activity of respiratory neurons (RN) of the medulla oblongata under normal and oxygen deficiency conditions. Under conditions of normal atmospheric pressure, the electrical stimulation of the CA1 and CA3 areas of the hippocampus had mainly an inhibiting influence. In the initial phase, at a 4-5-thousand meter altitude, activation of frequent discharge of neurons occurred.

Wide InP nanowires with wurtzite/zincblende superlattice segments are type-II whereas narrower nanowires become type-I: an atomistic pseudopotential calculation.

Nanowire-superlattices with different structural phases along the nanowire direction, such as wurtzite (WZ) and zincblende (ZB) forms of the same compound, often exhibit a "type II" band-alignment with electrons on ZB and holes on WZ. This is a material property of most of III-V semiconductors. We show via InP nanowires that as the nanowire diameter decreases, quantum-confinement alters this basic material property, placing both electrons and holes on the same (ZB) phase.

Crystal phase quantum dots.

In semiconducting nanowires, both zinc blende and wurtzite crystal structures can coexist. The band structure difference between the two structures can lead to charge confinement. Here we fabricate and study single quantum dot devices defined solely by crystal phase in a chemically homogeneous nanowire and observe single photon generation.

[Determination of the role of the hypothalamic lateral mammilar nucleus in regulation of neurons in the respiratory center of rat's medulla during hypoxia].

The pulse activity of medullar respiration center neurons and rat's respiration as a function of excitation of the lateral mammillary (LM) nucleus of the hypothalamus were studied in differing hypoxic conditions. Electrical stimulation of the LM nucleus in normoxia had a predominantly activating effect. A moderate pO2 fall at the start of "ascent" to 4000-5000 m increased pulsation of the respiratory neurons.

Selective excitation and detection of spin states in a single nanowire quantum dot.

We report exciton spin memory in a single InAs(0.25)P(0.75) quantum dot embedded in an InP nanowire.

[Reaction of respiration neurons in the medulla on locus coeruleus irritation by hypoxia].

Effects of locus coeruleus (LC) stimulation on the impulse activity of bulbar respiration neurons in rats were studied on a background of varying hypoxia. Different levels of hypoxia were used as an experiment model for ensuing summation of the LC effect. At the normal atmospheric pressure, LC electrical stimulation had an alleviating and also inhibiting effect on the impulse activity of these medulla neurons; however, the former effect was dominant.

[Efficiency of an arbitrary respiratory rhythm reducing method in students of special medical physical educational groups].

Three-month decreased voluntary optimum respiration rate (DVORR) trainings during therapeutic exercises in students with various abnormalities caused increases in vital capacity and chest circumference amplitude. DVORR also affected cardiovascular performance. During exercises, heart rate decreased and pulse pressure increased, suggesting economized cardiac performance and better myocardial function.

[Influence of cholinergic and adrenergic agents of the electric activity of the brain and the heart under hypoxia].

Injection of adrenergic and cholinergic agents to animals in the normal athmospheric conditions did not tigger drastic changes on the electric activity of the brain and heart. Acutehipoxia demands high adaptability from the body. In such conditions stimulation of reticular formation and hypothalamus produces different changes in the EEG and ECG activity whith injecting adrenergic and cholinergic agents.

Entangled photon pairs from semiconductor quantum dots.

Tomographic analysis demonstrates that the polarization state of pairs of photons emitted from a biexciton decay cascade becomes entangled when spectral filtering is applied. The measured density matrix of the photon pair satisfies the Peres criterion for entanglement by more than 3 standard deviations of the experimental uncertainty and violates Bell's inequality. We show that the spectral filtering erases the "which path" information contained in the photons' color and that the remanent information in the quantum dot degrees of freedom is negligible.

[Effects of adrenergic substances on the cardiac rhythm and electrical activity of the brain in rabbits during hypoxia].

The paper reports the effects of alpha and beta-adrenergic substances on the cardiac rhythm and electrical activity of the brain under the hypoxic conditions. beta-adrenergic substances were shown to have a stronger influence on these parameters as compared with alpha-adrenergic. The neoepinephrine effects were pronounced before "lifting", while the propranolol effects increased "at the altitude".

[The limbical mechanisms of regulations of respiratory neurons in hypoxia conditions].

The structures of limbic system have great integration in vegetative reactions. In the oxygen deficiency conditions we studied influence of irritation of limbical cortex, orbitofrontal cortes, hipotalamys, septum and hippocampus (CA1 and CA3 areas) on the impulse activity of respiratory neurons. Phases of hypoxia were the model of experiment.

[Response of respiratory neurons of the medulla oblongata to the septum stimulation in hypoxia].

In the oxygen deficiency conditions, we studied influence of irritation of ventral (BNST), lateral (LSN) and medial (MSN) nuclei of the septum on the impulse activity of the bulbar respiratory neurons and on respiration. Phases of hypoxia were the model of experiment. In conditions of normal atmospheric pressure, the electrical stimulation of BNST, LSN and MSN nuclei of the septum exerted inhibiting as well as activating influence with the inhibiting influence prevailing.