First-order melting transition of an Abrikosov vortex lattice

We report resutls of extensive Monte Carlo simulations of a three-dimensional model system containing the essential physics required to describe the melting of an unpinned Abrikosov lattice in an extreme type-II superconductor. A first-order phase transition is found. At the field which we have studied, corresponding very roughly to a field of 10 T along the c axis in ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_7$, the latent heat of melting is ≃0.3${\mathit{k}}_{\mathit{B}}$T per vortex per layer.