Topological phase transitions between chiral and helical spin textures in a lattice with spin-orbit coupling and a magnetic field

We consider the combined effects of large spin-orbit couplings and a perpendicular magnetic field in a 2D honeycomb fermionic lattice. This system provides an elegant setup to generate versatile spin textures propagating along the edge of a sample. The spin-orbit coupling is shown to induce topological phase transitions between a helical quantum spin Hall phase and a chiral spin-imbalanced quantum Hall state. Besides, we find that the spin orientation of a single topological edge state can be tuned by a Rashba spin-orbit coupling, opening an interesting route towards quantum spin manipulation. We discuss the possible realization of our results using cold atoms trapped in optical lattices, where large synthetic magnetic fields and spin-orbit couplings can be engineered and finely tuned. In particular, this system would lead to the observation of a time-reversal-symmetry-broken quantum spin Hall phase.Comment: 8 pages, 3 figures, Accepted in Europhys. Lett. (Dec 2011

Procedural law development stages

The procedural legal norms play a very important role in ensuring optimal conditions for legal regulation, bear the main burden of the normative way of strengthening the rule of law, ensuring the rights, freedoms and legitimate interests of citizens. It is obvious that it is impossible to determine the trends in the procedural law development as an independent legal unit, to predict ways of optimizing and unifying certain process types in different legal families without a historical excursio

STEM nanoanalysis of Au/Pt/Ti-Si3N4 interfacial defects and reactions during local stress of SiGe HBTs

A new insight on the behavior of metal contact-insulating interfaces in SiGe heterojunction bipolar transistor is given by high-performance aberration-corrected scanning transmission electron microscopy (STEM) analysis tools equipped with sub-nanometric probe size. It is demonstrated that the presence of initial defects introduced during technological processes play a major role in the acceleration of degradation mechanisms of the structure during stress. A combination of energy-filtered transmission electron microscopy analysis with high angle annular dark field STEM and energy dispersive spectroscopy provides strong evidence that migration of Au-Pt from the metal contacts to Ti/Si3N4 interface is one of the precursors to species interdiffusion and reactions. High current densities and related local heating effects induce the evolution of the pure Ti initial layer into mixture layer composed of Ti, O, and N. Local contamination of Ti layers by fluorine atoms is also pointed out, as well as rupture of TiN thin barrier layer

Electric double-layer capacitance between an ionic liquid and few-layer graphene

Ionic-liquid gates have a high carrier density due to their atomically thin electric double layer (EDL) and extremely large geometrical capacitance C-g. However, a high carrier density in graphene has not been achieved even with ionic-liquid gates because the EDL capacitance C-EDL between the ionic liquid and graphene involves the series connection of C-g and the quantum capacitance C-q, which is proportional to the density of states. We investigated the variables that determine C-EDL at the molecular level by varying the number of graphene layers n and thereby optimising C-q. The C-EDL value is governed by C-q at n, 4, and by C-g at n > 4. This transition with n indicates a composite nature for C-EDL. Our finding clarifies a universal principle that determines capacitance on a microscopic scale, and provides nanotechnological perspectives on charge accumulation and energy storage using an ultimately thin capacitor

TECHNICAL LIMITS FOR DEVELOPMENT OF NATURAL GAS HYDRATE DEPOSITS

In this work we have formulated the set criteria for cost-effective selection of technologies for industrial production of gas from a hydrate deposit, which rely on the properties of hydrate-bearing rock and the geologic properties of the gas hydrate deposit. For over forty years the world’s energy industry has been trying to effectively master vast unconventional resources of natural gas – the natural gas hydrates [1;3;4]. Specialists have accumulated during this period of time a great deal of knowledge about gas hydrates [8;10]. They established the conditions of hydrate formation in sedimentary rock and the conditions of formation and disappearance of gas hydrate deposits, and offered several classification methods for gas hydrate deposits. Specialists have proposed several methods to locate the gas hydrate accumulations on land and offshore and determined the probable areas where gas hydrate deposits may exist. More than 220 gas hydrate deposits were found to-date, and methods to calculate the amount of gas in a hydrate deposit were developed [1;12]. The principles of gas production from a hydrate deposit were formulated and real experience of commercial natural gas production from a hydrate deposit was gained. However, until now there were no set economic criteria for selection of effective technologies for industrial development of gas hydrate deposits. This results in periodic development of various models not applicable to specific geologic conditions.Non UBCUnreviewe

Nonpharmacological Strengthening of Fibrinolysis in Complex Therapy of Primary Open-Angle Glaucoma

Purpose: to study the effect of dosed pneumatic vasocompression (DPVK) on the functional parameters of the organ of vision in patients with primary open-angle gluacoma in the complex therapy of this form of pathology.Patients and Methods. The study included 39 patients with stage II POAG, which were randomized into two groups: main and control. All patients received a conservative complex drug therapy. Patients of the main group were additionally conducted DPVK sessions — twice a week (only 4 procedures during the entire course of treatment). All patients underwent standard ophthalmologic examination, hemostasis and fibrinolysis.Results. In the main group of patients, 1 hour after the end of compression, an increase (from baseline) in t-PA level (by median — 1.4 times) was observed while reducing the content of PAI-1 (by median — 2.7 times); improvement of hydrodynamic indicators (improvement of the outflow lightness coefficient, by 19.04 % in OD and 20.0 % in OS, decrease in KB by 24.7 % in OD and by 22.3 % in OS from the initial level) and retinal sensitivity (decrease the number of cattle type 1 in both eyes: 1.70 times on OD and 2.14 times on OS, decrease in type 2 cattle by 2.70 (OD) and 2.30 times (OS). In this regard, an increase sites of normal retina’s photosensitivity in 1.14 times on the OD and 1.19 times on the OS, in contrast to patients in the control group, where no significant changes were found.Conclusion. The obtained preliminary results of the study indicate the prospects for non-pharmacological stimulation of fibrinolysis in the inpatient stage of the addition of conservative therapy in patients with POAG, achieved with a course of dosed pneumatic vasocompression