Vortex lines interaction in the three-dimensional magnetic Ginzburg--Landau model
Carlos Román, Etienne Sandier, Sylvia Serfaty
TL;DR
The paper analyzes the three-dimensional Ginzburg–Landau functional with gauge field in the London limit ε→0 near the first vortex onset field H_c1. It derives a next-order expansion for H_c1, shows vortices appear one by one and concentrate near a special isoflux curve Γ_0, and introduces a renormalized energy W_N governing the interaction of multiple vortex filaments via a horizontal blow-up. The main contribution is a sharp Γ-convergence framework that combines 3D lower bounds (via Rom’s method and slicing) with a novel Biot–Savart-based upper bound construction, yielding precise energy expansions and vortex configurations that minimize W_N. This work clarifies the shape and arrangement of vortex lines in 3D superconductors, revealing curvature effects and boundary interactions that cause lines to bend near Γ_0 and to organize into nearly parallel, curved filaments dictated by the geometry of the isoflux problem.
Abstract
We complete our study of the three dimensional Ginzburg--Landau functional with magnetic field, in the asymptotic regime of a small inverse Ginzburg--Landau parameter $\varepsilon$, and near the first critical field $H_{c_1}$ for which the first vortex filaments appear in energy minimizers. Under a nondegeneracy condition, we show a next order asymptotic expansion of $H_{c_1}$ as $\varepsilon \to 0$, and exhibit a sequence of transitions, with vortex lines appearing one by one as the intensity of the applied magnetic field is increased: passing $H_{c_1}$ there is one vortex, then increasing $H_{c_1}$ by an increment of order $\log |\log\varepsilon|$ a second vortex line appears, etc. These vortex lines accumulate near a special curve $Γ_0$, solution to an isoflux problem. We derive a next order energy that the vortex lines must minimize in the asymptotic limit, after a suitable horizontal blow-up around $Γ_0$. This energy is the sum of terms where penalizations of the length of the lines, logarithmic repulsion between the lines and magnetic confinement near $Γ_0$ compete. This elucidates the shape of vortex lines in superconductors.
