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arXiv · 0708.1092

Spin-orbital Kondo decoherence by environmental effects in capacitively coupled quantum dot devices

Sabine Andergassen·Pascal Simon·Serge Florens·Denis Feinberg
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Abstract

Strong correlation effects in a capacitively coupled double quantum-dot setup were previously shown to provide the possibility of both entangling spin-charge degrees of freedom and realizing efficient spin-filtering operations by static gate-voltage manipulations. Motivated by the use of such a device for quantum computing, we study the influence of electromagnetic noise on a general spin-orbital Kondo model, and investigate the conditions for observing coherent, unitary transport, crucial to warrant efficient spin manipulations. We find a rich phase diagram, where low-energy properties sensitively depend on the impedance of the external environment and geometric parameters of the system. Relevant energy scales related to the Kondo temperature are also computed in a renormalization-group treatment, allowing to assess the robustness of the device against environmental effects.

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Sabine Andergassen, Pascal Simon, Serge Florens, Denis Feinberg. 2007-10-22. Spin-orbital Kondo decoherence by environmental effects in capacitively coupled quantum dot devices. https://doi.org/10.1103/physrevb.77.045309

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