Kondo-type transport through a quantum dot under magnetic fields - art. no. 235306

In this paper, we investigate the Kondo correlation effects on linear and n onlinear transport in a quantum dot connected to reservoirs under finite ma gnetic fields, using the slave-boson mean field approach suggested by Kotli ar and Ruckenstein [Phys. Rev. Lett. 57, 1362 (1986)]. A brief comparison b etween the present formulation and other slave-boson formulation is present ed to justify this approach. The numerical results show that the linear con ductance near electron-hole symmetry is suppressed by the application of th e magnetic fields, but an anomalous enhancement is predicted in the nonsymm etry regime. The effect of external magnetic fields on the nonlinear differ ential conductances is discussed for the Kondo system. A significant reduct ion of the peak splitting is observed due to the strong Kondo correlation, which agrees well with experimental data.