Kondo effect in a three-terminal geometry
In this manuscript, we are interested in a quantum dot connected to three reservoirs. The Kondo cloud essentially develops in the third reservoir which is strongly coupled to the quantum dot. The other two reservoirs are weakly coupled to the quantum dot and are used to probe the system by transport measurements. After modeling such a three-terminal geometry, we have calculated the conductance matrix at zero temperature by Fermi liquids theory. In the remaining of the manuscript, we focus on the case where the third reservoir has a finite size, which confers to its density of state a peaks structure. We have first studied the system by the perturbative renormalisation group and have evaluated the Kondo temperature, which is the main energy scale of the problem. Next, we have calculated the conductance matrix of the system at different temperatures. For temperatures much stronger than the Kondo temperature, we have used a perturbative approach. For temperatures much weaker than the Kondo temperature, we have used a Fermi liquid type theory. In the intermediate regime, we have used a numerical method called slave bosons mean field theory. In the latter regime, we have also performed a spectroscopic analysis of the dot density of states.