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arXiv · 0710.5554

Frustration of decoherence in $Y$-shaped superconducting Josephson networks

D. Giuliano·P. Sodano
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Abstract

We examine the possibility that pertinent impurities in a condensed matter system may help in designing quantum devices with enhanced coherent behaviors. For this purpose, we analyze a field theory model describing Y- shaped superconducting Josephson networks. We show that a new finite coupling stable infrared fixed point emerges in its phase diagram; we then explicitly evidence that, when engineered to operate near by this new fixed point, Y-shaped networks support two-level quantum systems, for which the entanglement with the environment is frustrated. We briefly address the potential relevance of this result for engineering finite-size superconducting devices with enhanced quantum coherence. Our approach uses boundary conformal field theory since it naturally allows for a field-theoretical treatment of the phase slips (instantons), describing the quantum tunneling between degenerate levels.

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D. Giuliano, P. Sodano. 2008-07-06. Frustration of decoherence in $Y$-shaped superconducting Josephson networks. https://doi.org/10.1088/1367-2630%2F10%2F9%2F093023

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