Orbital Magnetism of 2D Chaotic Lattices

We study the orbital magnetism of 2D lattices with chaotic motion of electrons withing a primitive cell. Using the temperature diagrammatic technique we evaluate the averaged value and rms fluctuation of magnetic response in the diffusive regime withing the model of non-interacting electrons. The fluctuations of magnetic susceptibility turn out to be large and at low temperature can be of the order of $\chi_{L} (k_{F}l)^{3/2}$, where $k_{F}$ is the Fermi wavevector, $l$ is the mean free path, and $\chi_{L}$ is the Landau susceptibility. In the certain region of magnetic fields the paramagnetic contribution to the averaged response is field independent and larger than the absolute value of Landau response.