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arXiv · 0911.2886

Interplay between Kondo physics and spin-orbit coupling in carbon nanotube quantum dots

Martin R. Galpin·Frederic W. Jayatilaka·David E. Logan·Frithjof B. Anders
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Abstract

We investigate the influence of spin-orbit coupling on the Kondo effects in carbon nanotube quantum dots, using the numerical renormalization group technique. A sufficiently large spin-orbit coupling is shown to destroy the SU(4) Kondo effects at zero magnetic field, leaving only two SU(2) Kondo effects in the one- and three-electron Coulomb blockade valleys. On applying a finite magnetic field, two additional, spin-orbit induced SU(2) Kondo effects arise in the three- and two-electron valleys. Using physically realistic model parameters, we calculate the differential conductance over a range of gate voltages, temperatures and fields. The results agree well with measurements from two different experimental devices in the literature, and explain a number of observations that are not described within the standard framework of the SU(4) Anderson impurity model.

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Martin R. Galpin, Frederic W. Jayatilaka, David E. Logan, Frithjof B. Anders. 2009-11-15. Interplay between Kondo physics and spin-orbit coupling in carbon nanotube quantum dots. https://doi.org/10.1103/physrevb.81.075437

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