Transport through a strongly correlated quantum dot with Fano interference

We present transport properties of a strongly correlated quantum dot attached to two leads with a side coupled noninteracting quantum dot. Transport properties are analyzed using the slave boson mean field theory which is reliable in the zero temperature and low bias regime. It is found that the transport properties are determined by the interplay of two fundamental physical phenomena, i.e., the Kondo effects and the Fano interference. The linear conductance will depart from the unitary limit and the zero bias anomaly will be suppressed in the presence of interdot coupling. The zero bias shot noise Fano factor in mean field approximation varies with the interdot coupling and tends to the Poisson value. We find nonmonotonic increase of the shot noise Fano factor with the interdot coupling, which cannot be obtained within the noninteracting model.

Figure 1

Schematic plot of the nanodevice. Only one quantum dot QD0 is connected with both leads. Another noninteracting quantum dot QD1 is side coupled to QD0. Energy level of QD1 can be adjusted via the gate voltage or a magnetic field.

Figure 2

(Color online) Density of states at QD0 ${\rho }_0$ for different coupling strength $t_c$. The energy level of QD1 is fixed at $-T_K^0$.

Figure 3

Differential conductance as a function of the applied voltage for various interdot couplings $t_c=0$, 0.03, 0.04, and 0.05. The energy level of QD1 is fixed at $T_K^0$.

Figure 4

(Color online) Differential conductance with different side dot energy levels. The interdot coupling is fixed at $t_c=0.04\Gamma$.

Figure 5

(Color online) Bias dependence of the shot noise Fano factor $\gamma$ with different interdot coupling parameters. The side dot energy level is fixed at ${ϵ}_1=T_K^0$.

Figure 6

(Color online) Fano factor as a function of the interdot coupling strength for different ${ϵ}_1$. The bias is fixed at $V_{LR}=T_K^0$.