The bifurcation of symmetric superconducting solutions from the normal solution is
considered for the one-dimensional Ginzburg–Landau equations by the methods of formal
asymptotics. The behaviour of the bifurcating branch depends upon the parameters d, the
size of the superconducting slab, and κ, the Ginzburg–Landau parameter. It was found
numerically by Aftalion & Troy [1] that there are three distinct regions of the
(κ, d) plane, labelled S1, S2 and
S3, in which there are at most one, two and three symmetric solutions
of the Ginzburg–Landau system, respectively. The curve in the
(κ, d) plane across which the bifurcation switches from being subcritical to
supercritical is identified, which is the boundary between
S2 and S1∪S3,
and the bifurcation diagram is analysed in its vicinity. The triple point,
corresponding to the point at which S1, S2 and
S3 meet, is determined, and the bifurcation
diagram and the boundaries of S1, S2 and
S3 are analysed in its vicinity. The results provide
formal evidence for the resolution of some of the conjectures of
Aftalion & Troy [1].