Critical Magnetic Field and Asymptotic Behavior of Superconducting Thin Films
نویسندگان
چکیده
In this paper, we discuss the vortex structure of the superconducting thin films placed in a magnetic field. The discussion is based on a system of simplified Ginzburg–Landau equations. We obtain the estimate for the lower critical magnetic field Hc1 , in the sense that it is the first critical value of hex, the applied field, for which the minimal energy among vortexless configurations is equal to the minimal energy among single-vortex configurations; moreover, it corresponds to the first phase transition in which vortices appear in the superconductor. We also discuss the location of these vortices and the asymptotic behavior of the local minimizers.
منابع مشابه
Three-dimensional calculations of the magnetic fields in a finite superconducting hollow cylinder in an applied axial magnetic field
In this study, a set of self-consistent coupled-integral equations for the local magnetic flux and current distributions in a finite superconducting hollow cylinder under an axial magnetic field has been directly derived by using the Biot-Savart law within the framework of the critical-state model. The equations were first solved numerically in the three-dimensional space before obtaining the h...
متن کاملOn Ginzburg–Landau Vortices of Superconducting Thin Films
In this paper, we discuss the vortex structure of the superconducting thin films placed in a magnetic field. We show that the global minimizer of the functional modelling the superconducting thin films has a bounded number of vortices when the applied magnetic field hex < Hc1 +K log | log ε| where Hc1 is the lower critical field of the film obtained by Ding and Du in SIAM J. Math. Anal., 2002. ...
متن کاملMagnetic-field-induced anomalous microwave response in superconducting YBa2Cu3O7Àd thin films
The magnetic-field-induced decrease of microwave surface impedance, Zs5Rs1 jXs , of superconducting YBa2Cu3O72d thin films is investigated using a microstrip resonator technique. Through measuring Zs as the direct current ~dc! magnetic field is increased from zero to a certain value Hmax and subsequently decreased back to zero, it is found that Zs(Hdc) is totally reversible if Hmax does not exc...
متن کامل1 Suppression of Superconducting Critical Current Density by Small Flux Jumps in MgB 2 Thin Films
By doing magnetization measurements during magnetic field sweeps on thin films of the new superconductor MgB2, it is found that in a low temperature and low field region small flux jumps are taking place. This effect strongly suppresses the central magnetization peak leading to reduced nominal superconducting critical current density at low temperatures. A borderline for this effect to occur is...
متن کاملA Hierarchy of Models for Superconducting Thin Films
A hierarchy of models for type-II superconducting thin films is presented. Through appropriate asymptotic limits this hierarchy passes from the mesoscopic Ginzburg-Landau model to the London model with isolated vortices as δfunction singularities, to vortex-density models and finally to macroscopic critical-state models. At each stage it is found that a key nondimensional parameter is Λ = λ2/dL...
متن کاملذخیره در منابع من
با ذخیره ی این منبع در منابع من، دسترسی به آن را برای استفاده های بعدی آسان تر کنید
عنوان ژورنال:
- SIAM J. Math. Analysis
دوره 34 شماره
صفحات -
تاریخ انتشار 2002