Critical current density of a YNi2B2C superconductor in the two-band Ginzburg-Landau model

An analytical formula is obtained for the temperature dependence of the critical current density of a two-band superconductor. In deriving the formula, linearized equations of the two-band Ginzburg-Landau theory are used and the results are compared with the experimental data for YNi₂B₂C.     

The discreteness of the spectrum of the Schrödinger operator equation and some properties of the s‐numbers of the inverse Schrödinger operator

In this article, we investigate the discreteness and some other properties of the spectrum for the Schrödinger operator L defined by the formula on the space L₂(H, [0, ∞)) , where H is a Hilbert space. For the first time, an estimate is obtained for sum of the s‐numbers of the inverse Schrödinger operator. The obtained results were applied to the Laplace's equation in an angular region.