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Quantum phase transition in capacitively coupled double quantum dots

Martin R. Galpin·David E. Logan·H. R. Krishnamurthy
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Abstract

We investigate two equivalent, capacitively coupled semiconducting quantum dots, each coupled to its own lead, in a regime where there are two electrons on the double dot. With increasing interdot coupling a rich range of behavior is uncovered: first a crossover from spin- to charge-Kondo physics, via an intermediate SU(4) state with entangled spin and charge degrees of freedom; followed by a quantum phase transition of Kosterlitz-Thouless type to a non-Fermi liquid `charge-ordered' phase with finite residual entropy and anomalous transport properties. Physical arguments and numerical renormalization group methods are employed to obtain a detailed understanding of the problem.

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Martin R. Galpin, David E. Logan, H. R. Krishnamurthy. 2005-05-17. Quantum phase transition in capacitively coupled double quantum dots. https://doi.org/10.1103/physrevlett.94.186406

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