Low frequency excitations in the Coulomb Glass: numerical analysis using the avalanche method

We develop a numerical method, which allows to find pairs of metastable states differing by transition of several electrons. We show that at low temperature these pairs can be treated as local metastable systems that determine low-frequency properties of Coulomb Glass with low external disorder. The contribution of these pairs to low-frequency properties is suppressed when the strength of the external disorder becomes comparable with interaction between neighboring electrons.