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Correlation-induced suppression of decoherence in capacitively coupled Cooper-pair boxes

J. Q. You·Xuedong Hu·Franco Nori
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Abstract

Charge fluctuations from gate bias and background traps severely limit the performance of a charge qubit in a Cooper-pair box (CPB). Here we present an experimentally realizable method to control the decoherence effects of these charge fluctuations using two strongly capacitively coupled CPBs. This coupled-box system has a low-decoherence subspace of two states. Our results show that the inter-box Coulomb correlation can help significantly suppress decoherence of this two-level system, making it a promising candidate as a logical qubit, encoded using two CPBs.

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J. Q. You, Xuedong Hu, Franco Nori. 2005-08-19. Correlation-induced suppression of decoherence in capacitively coupled Cooper-pair boxes. https://doi.org/10.1103/physrevb.72.144529

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