相关论文: Mathematical model of flux relaxation phenomenon
Vortex penetration and flux relaxation phenomenon carry the information about the pinning ability, and consequently current-carrying ability, of a type-II superconductor. However, the theoretical descriptions to these phenomena are…
We investigate the relaxation dynamics of magnetic vortex lines in type-II superconductors following rapid changes of the external driving current by means of an elastic line model simulated with Langevin molecular dynamics. A system of…
The information about the current-carrying ability of a type-II superconductor can be obtained by studying the flux relaxation and vortex penetration phenomena in the superconductor. In early studies, the infinite series models of the flux…
The current-carrying ability of a type-II superconductor is generally represented by its critical current density. This can be determined by measuring a flux relaxation process starting with a testing current density that is greater than or…
Vortex penetration affects the stability of a superconducting system and limits the possible application of the system. However, the mathematical description to this phenomenon is currently unavailable. Here I present a mathematical model…
We develop a theory of conductivity of type-II superconductors in the flux flow regime taking into account random spatial fluctuations of the system parameters, such as the gap magnitude $\Delta$(r) and the diffusion coefficient D(r). We…
Magnetic flux dynamics in type-II superconductors is studied within the model of a viscous nonlinear diffusion of vortices for various sample geometries. We find that time dependence of magnetic moment relaxation after the field is switched…
In the present study we investigate analytically the process of velocity and energy relaxation in two-phase flows. We begin our exposition by considering the so-called six equations two-phase model [Ishii1975, Rovarch2006]. This model…
Current-voltage measurements of type-II superconductors are described by a coarse-grained model of superconducting vortex dynamics. We find that the power spectra of the voltage fluctuations, and the noise power, are related to the large…
We study the non-equilibrium relaxation kinetics of interacting magnetic flux lines in disordered type-II superconductors at low temperatures by means of a three-dimensional elastic line model and Monte Carlo simulations. Investigating the…
We apply the flow equation method for studying the current-current response function of electron systems with the pairing instability. To illustrate the specific scheme in which the flow equation procedure determines the two-particle…
This tutorial summarizes recent advances in the convex relaxation of the optimal power flow (OPF) problem, focusing on structural properties rather than algorithms. Part I presents two power flow models, formulates OPF and their relaxations…
We use time- and angle-resolved photoemission to measure quasiparticle relaxation dynamics across a laser-induced superconducting phase transition in Bi2Sr2CaCu2O8+delta. Whereas low-fluence measurements reveal picosecond dynamics, sharp…
Transverse ac permeability measurements in Bi$_2$Sr$_2$CaCu$_2$O$_{8+\delta }$ single crystals at low fields and temperatures in a vortex configuration free of external forces show that the decrease of the critical current as measured by…
A superconductor is stable if it does not quench. Quench is a short-time physics problem. For its deeper understanding of, and how to avoid quench, the physics behind stability has to be analysed. A previously suggested dynamic relaxation…
This tutorial summarizes recent advances in the convex relaxation of the optimal power flow (OPF) problem, focusing on structural properties rather than algorithms. Part I presents two power flow models, formulates OPF and their relaxations…
We study flux penetration in a disordered type II superconductor by simulations of interacting vortices, using a Monte Carlo method for vortex nucleation. Our results show that a detailed description of the nucleation process yields a…
We study a mean-field model of superconducting vortices in a II-type superconductor. We prove the global solvability of the problem about a flux of superconducting vortices through a given domain and also analyse the regularity of weak…
Magnetic relaxation in a type-II superconductor is simulated for a range of temperatures (T) in a simple model of 2D Josephson junction array (JJA) with finite screening. The high-T phase, that is characterised by a single time scale…
Low-temperature dissipation due to vortex motion in strongly anisotropic type-II superconductors with a moderate disorder ($\Delta^2/E_F \ll \hbar/\tau \ll \Delta$) is shown to be determined by the Zener-type transitions between the…