Datensatz

Zusammenfassung

The conductivity sigma(T) of a two-dimensional weakly disordered square lattice is studied at half-filling in the presence of the electron-electron correlations. The particle- hole symmetry, existing in the energy spectrum at half-filling, results in quantum corrections to sigma(T). The negative interaction contribution to sigma(T) in the weak localization regime, taking place far from half-filling, changes the sign due to the Bragg reflection assisted quantum corrections, and sigma(T) logarithmically increases with decreasing the temperature as half-filling is approached.