Flux-flow induced giant magnetoresistance in all-amorphous superconductor-ferromagnet hybrids

We present magnetoresistance measurements on all-amorphous ferromagnet (F) / superconductor (S) heterostructures. The F/S/F trilayers show large magnetoresistance peaks in a small field range around the coercive field of the F layers, at temperatures within and below the superconducting transition. This is interpreted as flux flow of weakly pinned vortices induced by the stray field of Bloch magnetic domains in the F layers. Bilayers show much smaller effects, implying that the Bloch walls of the F-layers in the trilayer line up and focus the stray fields. The data are used to discuss the expected minimum F-layer thickness needed to nucleate vortices.Comment: 6 pages, 6 figure

On the gravitational motion of a nonuniformly heated solid particle in a gaseous medium

The steady motion of a nonuniformly heated spherical aerosol particle through a viscous gaseous medium is theoretically studied in the Stokes approximationyesBelgorod State Universit

Стратегія повного госпрозрахунку як основа економічної стабільності і конкурентоспроможності виробництва (підприємства)

The article deals with three types of economic relations of the enterprise. Definition of self-financing and self-financing. The schemes of the marketing system of management and marketing system of self-management by the enterprise are also shown.В статті розглядається три види економічних відносин підприємства. Надано визначення самоокупності та самофінансування. Також показані схеми маркетингової системи господарювання та маркетингової системи самоуправління підприємством

On the force acting on a heated spherical drop moving in a gaseous medlum

The flow around a heated spherical drop in a viscous non-isothermal gaseous medium with uniformly distributed constant-power heat sources (sinks) acting inside is theoretically described in the Stokes approximationyesBelgorod State Universit

Two-dimensional Ising model with competing interactions and its application to clusters and arrays of π\pi-rings and adiabatic quantum computing

We study planar clusters consisting of loops including a Josephson $\pi$-junction ($\pi$-rings). Each $\pi$-ring carries a persistent current and behaves as a classical orbital moment. The type of particular state associated with the orientation of orbital moments at the cluster depends on the interaction between these orbital moments and can be easily controlled, i.e. by a bias current or by other means. We show that these systems can be described by the two-dimensional Ising model with competing nearest-neighbor and diagonal interactions and investigate the phase diagram of this model. The characteristic features of the model are analyzed based on the exact solutions for small clusters such as a 5-site square plaquette as well as on a mean-field type approach for the infinite square lattice of Ising spins. The results are compared with spin patterns obtained by Monte Carlo simulations for the 100 $\times$ 100 square lattice and with experiment. We show that the $\pi$-ring clusters may be used as a new type of superconducting memory elements. The obtained results may be verified in experiments and are applicable to adiabatic quantum computing where the states are switched adiabatically with the slow change of coupling constants.Comment: 32 pages, 22 figures, RevTe

Підвищення ефективності самопланування основних результатів діяльності будівельних підприємств

The article considers the possibilities of increasing the efficiency of self-planning of the main results of the activity of construction enterprises.  In a marketing system of production and management planning is carried out on the basis of the economic mechanism of self-planning, taking into account the state orientation and guiding planning through the development of short-term, medium-term, long-term, as well as strategic in the form of major strategies and specific business plans.The process of effective self-planning is proposed to be carried out by identifying the main areas for increasing the efficiency of activities and developing the main economic indicators. Also presented is a sequence diagram of the process of ensuring the effectiveness of self-planning.В статті розглядаються можливості підвищення ефективності самопланування основних результатів діяльності будівельних підприємств. Також показано основні характеризуючі показники та представлена схема послідовності процесу забезпечення ефективності самопланування

Proximity-driven source of highly spin-polarized ac current on the basis of superconductor/weak ferromagnet/superconductor voltage-biased Josephson junction

We theoretically investigate an opportunity to implement a source of highly spin-polarized ac current on the basis of superconductor/weak ferromagnet/superconductor (SFS) voltage-biased junction in the regime of essential proximity effect and calculate the current flowing through the probe electrode tunnel coupled to the ferromagnetic interlayer region. It is shown that while the polarization of the dc current component is generally small in case of weak exchange field of the ferromagnet, there is an ac component of the current in the system. This ac current is highly spin-polarized and entirely originated from the non-equilibrium proximity effect in the interlayer. The frequency of the current is controlled by the voltage applied to SFS junction. We discuss a possibility to obtain a source of coherent ac currents with a certain phase shift between them by tunnel coupling two probe electrodes at different locations of the interlayer region.Comment: 8 pages, 5 figure

The current-phase relation in Josephson tunnel junctions

The $J(\phi)$ relation in SFIFS, SNINS and SIS tunnel junctions is studied. The method for analytical solution of linearized Usadel equations has been developed and applied to these structures. It is shown that the Josephson current across the structure has the sum of $\sin \phi$ and $\sin 2\phi$ components. Two different physical mechanisms are responsible for the sign of $\sin 2\phi$. The first one is the depairing by current which contributes positively to the $\sin 2\phi$ term, while the second one is the finite transparency of SF or SN interfaces which provides the negative contribution. In SFIFS junctions, where the first harmonic vanishes at 0 - $\pi$ transition, the calculated second harmonic fully determines the $J(\phi)$ curve.Comment: 6 pages, 2 figure