Abstract
This paper introduces a semi-analytical method for calculating the Hall conductivity in the single-band approximation. The method goes beyond the linear response theory and thus, it formally imposes no limitation on the electric-field magnitude. It is shown that, when the Bloch frequency exceeds the cyclotron frequency, the Hall current decreases with increasing electric field. The obtained results can be directly applied to the cold Bose atoms in a 2D optical lattice, where the single-band approximation is well justified.