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Figure 2 | Nanoscale Research Letters

Figure 2

From: Analytical expression of Kondo temperature in quantum dot embedded in Aharonov-Bohm ring

Figure 2

Schematic drawing of the density of states in the lead for the reduced model, in situations (a) L c L K L , (b) L c L L K , and (c) L L c L K , where L is the size of the AB ring, L c is the screening length of charge fluctuation, and L K is that of spin fluctuation, i.e., size of Kondo screening cloud. The half of band width is D 1 |ε 0| in the second stage of scaling. In situation (a), ε T T K |ε 0|. The oscillating part of ν(ε k ) is averaged out in the integration of scaling equations. In consequence, the Kondo temperature T K does not depend on the ring size nor AB phase ϕ of the magnetic flux penetrating the ring. In situation (b), T K ε T |ε 0|. Then the Thouless energy ε T acts as the high energy cut off. ϕ-dependence of T K is determined by the ratio of ε T to T K. In situation (c), T K |ε 0| ε T. The density of states is almost constant. In this case, T K reflects the density of states at the Fermi level, ν(0).

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