By extending the supersymmetry formalism we develop a statistical description for the conductance through a quantum dot coupled to external leads with point contacts. The electronic states inside the dot are formed by both the random and regular parts of confinement potential and have a finite lifetime due to the presence of the external contacts. The explicit form of the distribution function for the one-channel conductance is obtained. This function depends in a universal way on the transmission coefficients between the dot and the leads. The generalization of the results for the low-frequency impedance of the dot is suggested.

• Received 31 January 1995

DOI:https://doi.org/10.1103/PhysRevB.51.17223