Superconductor-Insulator Transition in a Disordered Electronic System

We study an electronic model of a 2D superconductor with onsite randomness using Quantum Monte Carlo simulations. The superfluid density is used to track the destruction of superconductivity in the ground state with increasing disorder. The non-superconducting state is identified as an insulator from the temperature dependence of its d.c. resistivity. The value of $\sigma_{\rm dc}$ at the superconductor-insulator transition appears to be non-universal.