Effect of the Kondo correlation on shot noise in a quantum dot

The current noise in a quantum dot (QD) coupled to two leads is investigated in the Kondo regime with and without the influence of magnetic fields by employing a finite-U slave-boson mean-field approach to calculate the current-current correlation function at zero temperature. The numerical results show that the Fano factor is always reduced significantly due to the Kondo-correlation effect, and the most pronounced suppression appears at the electron-hole symmetry case 2epsilon(d) + U = 0. In addition, the application of a magnetic field enhances the Fano factor at small external voltage, which is attributed to the reduction of the Kondo-enhanced density of states and transmission probability in a QD.