We present a protected superconducting qubit based on an effective circuit element that only allows pairs of Cooper pairs to tunnel. These dynamics give rise to a nearly degenerate ground state manifold indexed by the parity of tunneled Cooper pairs. We show that, when the circuit element is shunted by a large capacitance, this manifold can be used as a logical qubit that we expect to be insensitive to multiple relaxation and dephasing mechanisms.

中文翻译：

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两库珀对隧穿保护的超导电路

我们提出一种基于有效电路元件的受保护超导量子比特，该电路元件仅允许成对的Cooper对隧穿。这些动力学产生了几乎简并的基态流形，其由隧穿的库珀对的奇偶性指示。我们证明，当电路元件被大电容分流时，该歧管可以用作逻辑qubit，我们期望它对多重张弛和移相机制不敏感。