Phase relaxation and non-equilibrium transport properties through multilevel quantum dot

Phase relaxation of conduction electrons in transport through a multilevel quantum dot in the Coulomb blockade region is studied using the Anderson Hamiltonian. Two types of currents are calculated separately, i.e., in the absence and presence of the phase relaxation. At low temperatures, the current without the phase relaxation is considerably suppressed for an appropriate value of the Coulomb interaction between electrons in the dot. This is due to the interference between two virtual processes in the transport of a electron. At high temperatures, the two types of currents are almost identical as a consequence of the thermal excitations.