Cat-state qubits (qubits encoded with cat states) have recently attracted much attention because of their enhanced lifetimes with quantum error correction. We here consider a circuit QED system consisting of three superconducting qutrits, each coupled to an individual cavity but all coupled to a common cavity. We show that entangled W states of three cat-state qubits hosted by the three individual cavities can be prepared with only a few basic operations. The higher energy level of the qutrits is not occupied; thus, decoherence from this level of the qutrits is greatly suppressed. In addition, the W states can be prepared deterministically. Numerical simulations show that high-fidelity production of the W states of three cat-state qubits is feasible with current circuit QED technology. This proposal is quite general and can be applied to create the proposed W states, with each cavity being a microwave or optical cavity and each qutrit being a three-level natural or artificial atom.

猫态量子位（用猫态编码的量子位）由于具有延长的量子误差校正寿命而最近备受关注。我们在这里考虑一个电路QED系统，该系统由三个超导量子态组成，每个量子态耦合到一个单独的腔体，但全部耦合到一个公共腔体。我们表明，由三个单独的腔体托管的三个猫态量子位的纠缠W态仅需几个基本操作即可准备。量子态的较高能级未被占用；因此，极大地抑制了来自该量子态水平的退相干。另外，可以确定地准备W状态。数值模拟表明，高保真度生产的W使用当前电路QED技术，三个猫状态量子位的状态是可行的。该提议非常笼统，可用于创建提议的W态，每个腔是微波或光学腔，每个量子态是三级天然或人造原子。