CONDUCTANCE OF A QUANTUM-DOT WITH A HUBBARD INTERACTION IN THE PRESENCE OF A BOSON FIELD

We theoretically study the conductance of a quantum dot on which there is an on-site Coulomb interaction of energy U as well as a boson-elec tron interaction of coupling constant g. The independent boson model i s used to describe the boson held. The conductance is calculated via a Landauer-type formula by the equations-of-motion method of the retard ed Green's function. An analytic and compact formula for the retarded Green's function is obtained with two effective self-energies which ar e renormalized by both electron-electron and boson-electron interactio ns. Our numerical results show that the presence of a boson held typic ally leads to sideband peaks and decreases the main peak related to th e Coulomb interaction. The sideband peak height is sensitive to boson- electron interaction coupling constant g. We also present the temperat ure dependence of the conductance in the presence of a boson held.