Diamagnetism of a Simple Disordered System

The diamagnetism of a model disordered system is calculated for low temperatures. If the magnetic field is not too large, the diamagnetic susceptibility per electron is large and proportional to $T^{\frac{-2\mathrm{}}{5}}$. For large fields, however, this susceptibility rapidly decreases. A new variational method is used to obtain these results.