All-electrical time-resolved spin generation and spin manipulation in n-InGaAs

We demonstrate all-electrical spin generation and subsequent manipulation by two successive electric field pulses in an n-InGaAs heterostructure in a time-resolved experiment at zero external magnetic field. The first electric field pulse along the $[1\bar10]$ crystal axis creates a current induced spin polarization (CISP) which is oriented in the plane of the sample. The subsequent electric field pulse along [110] generates a perpendicular magnetic field pulse leading to a coherent precession of this spin polarization with 2-dimensional electrical control over the final spin orientation. Spin precession is probed by time-resolved Faraday rotation. We determine the build-up time of CISP during the first field pulse and extract the spin dephasing time and internal magnetic field strength during the spin manipulation pulse.Comment: 5 pages, 4 figure

Photon reabsorption in fluorescent solar collectors

Understanding photon transport losses in fluorescence solar collectors is very important for increasing optical efficiencies. We present an analytical expression to characterize photon reabsorption in fluorescent solar collectors, which represent a major source of photon loss. A particularly useful universal form of this expression is found in the limit of high reabsorption, which gives the photon reabsorption probability in a simple form as a function of the absorption coefficient and the optical étendue of the emitted photon beam. Our mathematical model predicts fluorescence spectra emitted from the collector edge, which are in excellent agreement with experiment and provide an effective characterization tool for photon transport in light absorbing media

Effective Heisenberg model and exchange interaction for strongly correlated systems

We consider the extended Hubbard model and introduce a corresponding Heisenberg-like problem written in terms of spin operators. The derived formalism is reminiscent of Anderson's idea of the effective exchange interaction and takes into account nonlocal correlation effects. The results for the exchange interaction and magnetic susceptibility are expressed in terms of single-particle quantities, which can be obtained efficiently in realistic calculations of multiband systems. In the strongly spin-polarized limit, when the local magnetic moment is well-defined, the exchange interaction reduces to a standard expression of the density functional theory that has been successfully used in practical calculations of magnetic properties of real materials.Comment: Accepted to Physical Review Letter

The effect of thermo-mechanical treatment on phase composition, structure and properties of titanium alloy VT16. Low-temperature thermomechanical treatment processing of rod semiproducts design

Методами РЭМ, ПЭМ, РСФА, ДСК изучено влияние холодной деформации со степенями вытяжки от 0 до 45 % и последующего нагрева на 450, 500, 550 °С с выдержками 30, 90, 180 минут на фазовый состав, структуру и свойства высокопрочного титанового сплава ВТ16, закаленного с 850 °С. Показано, что в ходе прокатки закаленного прутка протекает деформационно-индуцированное превращение α′′→α′, которое практически завершается по достижении степени вытяжки 15%. Кроме того, при степени вытяжки 15% образуется незначительное количество фазы с ОЦК решеткой (βа) с аномально высоким периодом, её объемная доля возрастает по мере увеличения степени деформации.By methods of SEM, TEM, XRD, STA the effect of cold deformation with degree from 0 up to 45% and subsequent heating at 450, 500, 550°C with holding time 30, 90, 180 minutes on phase composition, structure and properties of high strength titanium alloy VT16 quenched from 850 °C. The possibility of strain induced α′′→α′ - transformation during rolling of quenched rod was shown to take place up to elongation degree 15%. In addition minor volume fraction of phase with BCC lattice with abnormally large spacing at elongation degree 15% is formed. It`s volume fraction increases with the deformation degree increasing.Программа развития УрФУ на 2013 год (п.2.1.1.1

Semiclassical treatment of logarithmic perturbation theory

The explicit semiclassical treatment of logarithmic perturbation theory for the nonrelativistic bound states problem is developed. Based upon $\hbar$-expansions and suitable quantization conditions a new procedure for deriving perturbation expansions for the one-dimensional anharmonic oscillator is offered. Avoiding disadvantages of the standard approach, new handy recursion formulae with the same simple form both for ground and exited states have been obtained. As an example, the perturbation expansions for the energy eigenvalues of the harmonic oscillator perturbed by $\lambda x^{6}$ are considered.Comment: 6 pages, LATEX 2.09 using IOP style