Ginzburg-Landau theory is used to study the properties of single vortices and
of the Abrikosov vortex lattice in a dx2โy2โ superconductor. For a single
vortex, the s-wave order parameter has the expected four-lobe structure in a
ring around the core and falls off like 1/r2 at large distances. The
topological structure of the s-wave order parameter consists of one
counter-rotating unit vortex, centered at the core, surrounded by four
symmetrically placed positive unit vortices. The Abrikosov lattice is shown to
have a triangular structure close to Tcโ and an oblique structure at lower
temperatures. Comparison is made to recent neutron scattering data.Comment: 4 pages, REVTeX, 3 figures available upon reques