相关论文: Critical state in type-II superconductors of arbit…
We give a theoretical description of the general critical states in which the critical currents in type-II superconductors are not perpendicular to the local magnetic induction. Such states frequently occur in real situations, e.g., when…
A theoretical framework is presented, which allows to explain many experimental facts related to pinning and cross-flow effects between flux tubes in type-II superconductors. It is shown that critical state principles, in the manner…
A thin flat superconductor of arbitrary shape and with arbitrary in-plane and out-of-plane anisotropy of flux-line pinning is considered, in an external magnetic field normal to its plane. It is shown that the general three-dimensional…
As an example for a seemingly simple but actually intricate problem, the Bean critical state is studied in a superconducting strip of finite thickness d and width 2w >> d placed in an oblique magnetic field. The analytical solution is…
A nonlinear dynamics of the thermal and electromagnetic instability of critical state in type II superconductors has been analysed taking into account effects of dissipation and dispersion. An existance of a nonlinear running waves…
A simple one dimensional model to simulate the establishment of the Bean critical state is introduced. It is shown that the dynamics of the flux lines as they enter the superconductor are dominated by `avalanches'. The distribution of…
The properties of a conventional type-II superconductor near the upper critical field are usually calculated using a perturbative expansion in the strength of the order parameter. Here we show that perturbation theory breaks down near the…
We consider the current density distribution function of a flux creep regime in type-II superconductors by mapping the flux creep process to the dynamics of a model with a self-organized criticality. We use an extremal Robin Hood type model…
An exact analytic representation of the critical state of a current-carrying type-II superconductor strip located inside a cylindrical magnetic cavity of high permeability is derived. The obtained results show that, when the cavity radius…
We discuss the microwave energy losses in superconductors in the critical state. The field-induced variations of the surface resistance are determined, in the framework of the Coffey and Clem model, by taking into account the distribution…
Recently demonstrated superconducting atom-chips provide a platform for trapping atoms and coupling them to solid-state quantum systems. Controlling these devices requires a full understanding of the supercurrent distribution in the…
We study the magnetization of a cylindrical type-II superconductor filament covered by a coaxial soft-magnet sheath and exposed to an applied transverse magnetic field. Examining penetration of magnetic flux into the superconductor core of…
A theory for the electromagnetic response of type-II superconductors close beyond the critical state is presented. Our formulation relies on general physical principles applied to the superconductor as a thermodynamic system. Equilibrium…
We consider superconductors of Type II near the transition from the 'bulk superconducting' to the 'surface superconducting' state. We prove a new $L^{\infty}$ estimate on the order parameter in the bulk, i.e. away from the boundary. This…
Continuous phase transitions are studied in a two dimensional nonequilibrium model with an infinite number of absorbing configurations. Spreading from a localized source is characterized by nonuniversal critical exponents, which vary…
The current distribution across the thickness of a current-carrying rectangular film in the Meissner state was established long ago by the London brothers. The distribution across the width is more complicated but was later shown to be…
We study the phase transition to the superconducting state taking into account the fluctuations of the order parameter and of the vector magnetic field and discuss the question of the order of transition occuring in this model. We use the…
A phase transition of the region of the superconductor near the point contact into a new nonequi- librium state at the critical density of nonequilibriumquasiparticles is observed.
The problem of the thermal and magnetic destruction of the critical state in composite superconductors is investigated. The initial distributions of temperature and electromagnetic field are assumed to be essentially inhomogeneous. The…
We study theoretically the space-time evolution of the thermal and electromagnetic perturbation in a superconductor with a nonlinear current-voltage characteristics in the flux creep regime. On the basis of a linear analysis of a set of…