Effect of Particle Loss on Current in a System of Aharonov-Bohm Ring with Embedded Quantum Dot

Abstract We consider effect of particle loss on the current in a system of an Aharonov-Bohm ring with an embedded quantum dot. In the system, the particle loss is assumed to occur at the ends of normal conducting lead and the quantum dot. The Keldysh Green’s function method is extended to the dissipative system, the formula of nonequilibrium current is derived. The effect of particle loss on differential conductance is examined numerically. Although the phase shift in differential conductance does not occur in the presence of particle loss, the particle loss at both ends of the lead reduces differential conductance. By contrast, the particle loss at a quantum dot widens the resonant curve of the differential conductance, and reduces the maximum value. In the presence of Coulomb interaction, the Hartree-Fock approximation is employed. Although the differential conductance has double peaks because of the stepwise total occupation number of the quantum dot, the effect of particle loss on differential conductance is the same as that in the absence of Coulomb interaction. The validity of our calculation method is discussed by referring to previous literature.