Coherent ultrafast spin-dynamics probed in three dimensional topological insulators

Topological insulators are candidates to open up a novel route in spin based electronics. Different to traditional ferromagnetic materials, where the carrier spin-polarization and magnetization are based on the exchange interaction, the spin properties in topological insulators are based on the coupling of spin- and orbit interaction connected to its momentum. Specific ways to control the spin-polarization with light have been demonstrated: the energy momentum landscape of the Dirac cone provides spin-momentum locking of the charge current and its spin. The directionality of spin and momentum, as well as control with light has been demonstrated. Here we demonstrate a coherent femtosecond control of spin-polarization for states in the valence band at around the Dirac cone.Comment: 14 pages, 4 figure

North-south asymmetry of geomagnetic and tropospheric events

The influences of the solar plasma on geomagnetic and atmospheric phenomena are considered. There are the north-south asymmetry in the reaction of the geomagnetic field, of the geopotential and of the pressure in the magnetically conjugate points relative to the direction of the interplanetary magnetic field. There are the synchronism between direction of the meridinal component of wind at the level of the tropopause and the direction of the interplanetary magnetic field. © 1974

Provision of Biological Safety in the Territory of the Republic of Tatarstan during Preparation and Holding of FIFA World Cup-2018 in Kazan

Objective – assessment of effectiveness of the measures for biological safety provision at potentially hazardous facilities in the territory of the Republic of Tatarstan in the process of preparation and holding of FIFA World Cup-2018 in Kazan. Materials and methods. Regulatory-legal acts covering the requirements to the provision of biological safety during the work with pathogenic biological agents, international guidelines and documents determining inter-agency collaboration between the Rospotrebnadzor Administration in the Republic of Tatarstan and other departments and inter-agency task forces (Office of the Federal Security Bureau of Russia in the Republic of Tatarstan, Counter-Terrorism Commission in the Republic of Tatarstan, etc) were studied. Results and discussion. Considered were managerial-methodological approaches and matters of inter-agency cooperation on biological safety provision during preparation and holding of FIFA World Cup-2018 in Kazan. Biological safety was examined through the prism of its provision while working with pathogenic biological agents at potentially hazardous biological facilities and  counterterrorism integrity of the objects. The guiding, directive document in the performance of the complex of measures on biological safety provision and inter-agency collaboration was the Order of the President of the Russian Federation dated May 09, 2017 No 202 “On peculiarities of application of reinforced security measures during holding of FIFA World Cup-2018 and FIFA Confederations Cup-2017 in Russia”. As the result of the measures conducted, biological safety, including counter-terrorism security of potentially hazardous biological objects and sanitary-epidemiological welfare, was fully provided

Preparation and characterization of stable aqueous suspensions of up-converting Er3+/Yb3+-doped LiNbO3 nanocrystals

The preparation of LiNbO3:Er3+/Yb3+ nanocrystals and their up-conversion properties have been studied. It is demonstrated that polyethyleneimine- (PEI) assisted dispersion procedures allow obtaining stable aqueous LiNbO3:Er3+/Yb3+ powder suspensions, with average size particles well below the micron range (100–200 nm) and the isoelectric point of the suspension reaching values well above pH 7. After excitation of Yb3+ ions at a wavelength of 980 nm, the suspensions exhibit efficient, and stable, IR-to-visible (green and red) up-conversion properties, easily observed by the naked eye, very similar to those of the starting crystalline bulk material

North-south asymmetry of geomagnetic and tropospheric events

The influences of the solar plasma on geomagnetic and atmospheric phenomena are considered. There are the north-south asymmetry in the reaction of the geomagnetic field, of the geopotential and of the pressure in the magnetically conjugate points relative to the direction of the interplanetary magnetic field. There are the synchronism between direction of the meridinal component of wind at the level of the tropopause and the direction of the interplanetary magnetic field. © 1974

North-south asymmetry of geomagnetic and tropospheric events

The influences of the solar plasma on geomagnetic and atmospheric phenomena are considered. There are the north-south asymmetry in the reaction of the geomagnetic field, of the geopotential and of the pressure in the magnetically conjugate points relative to the direction of the interplanetary magnetic field. There are the synchronism between direction of the meridinal component of wind at the level of the tropopause and the direction of the interplanetary magnetic field. © 1974

North-south asymmetry of geomagnetic and tropospheric events

The influences of the solar plasma on geomagnetic and atmospheric phenomena are considered. There are the north-south asymmetry in the reaction of the geomagnetic field, of the geopotential and of the pressure in the magnetically conjugate points relative to the direction of the interplanetary magnetic field. There are the synchronism between direction of the meridinal component of wind at the level of the tropopause and the direction of the interplanetary magnetic field. © 1974