# Séminaire commun LPT-LPTMS : Olga Dimitrova

## Olga Dimitrova

The free energy and the specific heat of the two-dimensional Gaussian random bond Ising model on a square lattice are found with high accuracy using graph expansion and analysis of continuation of the high-temperature series. At low temperatures the specific heat reveals a zero-temperature criticality described by the power law $C\propto T^1+\alpha$, with $\alpha= 0.65(10)$, the result confirmed independently by counting many-body states in finite size samples. The interpretation of the free energy in terms of droplet excitations gives the density of the two-level states, that follows a novel power law $\rho(\epsilon)\propto \epsilon^\alpha$ at low energies.

Date/Time : 29/03/2012 - 14:00