CALCULATION OF THE SHEAR MODULUS OF A 2-DIMENSIONAL VORTEX LATTICE

We have calculated the temperature-dependent shear modulus mu(T) of a vortex lattice in a two-dimensional superconductor. We include fluctua tions by expanding the Ginzburg-Landau free-energy functional in state s from the lowest Landau level, and evaluate the shear modulus by stan dard Monte Carlo techniques for rectangular samples containing up to 2 24 vortices. At the thermodynamic melting transition, which is apparen tly first order as found by previous workers, the shear modulus falls from a finite value in the solid phase to zero in the liquid. Despite the first-order transition, the magnitude of the drop may be near the universal value envisioned in dislocation-unbinding theories.