Evolution of the Kondo Effect in a Quantum Dot Probed by the Shot Noise

We measure the current and shot noise in a quantum dot (QD) in the Kondo regime to address the non-equilibrium properties of the Kondo effect. By systematically tuning the temperature and gate voltages to define the level positions in the QD, we observe an enhancement of the shot noise as temperature decreases below the Kondo temperature, which indicates that the two-particle scattering process grows as the Kondo state evolves. Below the Kondo temperature, the Fano factor defined at finite temperature is found to exceed the expected value of unity from the non-interacting model, reaching $1.8 \pm 0.2$.