Kondo Effect in Quantum Dots
Kondo effect in a quantum dot is discussed. In the standard Coulomb blockade setting, tunneling between the dot and leads is weak, the number of electrons in the dot is well-defined and discrete; Kondo effect may be considered in the framework of the conventional one-level Anderson impurity model. It turns out however, that the Kondo temperature TK in the case of weak tunneling is extremely low. In the opposite case of almost reflectionless single-mode junctions connecting the dot to the leads, the average charge of the dot is not discrete. Surprisingly, its spin may remain quantized: s = 1/2 or s = 0, depending (periodically) on the gate voltage. Such a “spin-charge separation” occurs because, unlike Anderson impurity, quantum dot carries a broad-band, dense spectrum of discrete levels. In the doublet state, Kondo effect with a significantly enhanced TK develops.
KeywordsGate Voltage Spin Mode Magnetic Impurity Discrete Level Luttinger Liquid
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