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Dynamics of capacitively coupled double quantum dots

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

We consider a double dot system of equivalent, capacitively coupled semiconducting quantum dots, each coupled to its own lead, in a regime where there are two electrons on the double dot. Employing the numerical renormalization group, we focus here on single-particle dynamics and the zero-bias conductance, considering in particular the rich range of behaviour arising as the interdot coupling is progressively increased through the strong coupling (SC) phase, from the spin-Kondo regime, across the SU(4) point to the charge-Kondo regime; and then towards and through the quantum phase transition to a charge-ordered (CO) phase. We first consider the two-self-energy description required to describe the broken symmetry CO phase, and implications thereof for the non-Fermi liquid nature of this phase. Numerical results for single-particle dynamics on all frequency scales are then considered, with particular emphasis on universality and scaling of low-energy dynamics throughout the SC phase. The role of symmetry breaking perturbations is also briefly discussed.

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Martin R. Galpin, David E. Logan, H. R. Krishnamurthy. 2006-08-08. Dynamics of capacitively coupled double quantum dots. https://doi.org/10.1088/0953-8984%2F18%2F29%2F002

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