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Low-Temperature Decoherence of Qubit Coupled to Background Charges

Alex Grishin·Igor V. Yurkevich·Igor V. Lerner
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Abstract

We have found an exact expression for the decoherence rate of a Josephson charge qubit coupled to fluctuating background charges. At low temperatures $T$ the decoherence rate $Γ$ is linear in $T$ while at high temperatures it saturates in agreement with a known classical solution which, however, reached at surprisingly high $T$. In contrast to the classical picture, impurity states spread in a wide interval of energies ($\gg T$) may essentially contribute to $Γ$.

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Alex Grishin, Igor V. Yurkevich, Igor V. Lerner. 2005-08-02. Low-Temperature Decoherence of Qubit Coupled to Background Charges. https://doi.org/10.1103/physrevb.72.060509

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