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Decoherence of flux qubits due to 1/f flux noise

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 نشر من قبل Yasunobu Nakamura
 تاريخ النشر 2006
  مجال البحث فيزياء
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We have investigated decoherence in Josephson-junction flux qubits. Based on the measurements of decoherence at various bias conditions, we discriminate contributions of different noise sources. In particular, we present a Gaussian decay function of the echo signal as evidence of dephasing due to $1/f$ flux noise whose spectral density is evaluated to be about $(10^{-6} Phi_0)^2$/Hz at 1 Hz. We also demonstrate that at an optimal bias condition where the noise sources are well decoupled the coherence observed in the echo measurement is mainly limited by energy relaxation of the qubit.



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