在无消相干子空间中确定性地实现多目标量子比特相位翻转门

Deterministic implementation of a controlled phase gate with multi-target qubits in decoherence-free subspace

基于腔的输入输出过程,在无消相干子空间中利用腔中束缚的2个原子编码成逻辑量子比特来确定性的实现多目标逻辑量子比特受控相位门.该方案不仅对抵御整体退相位错误是鲁棒的,而且容易实现.通过对相位门保真度的分析得知,该方案对腔衰减更加鲁棒,在中度耦合条件下,它的保真度可以达到1.最后,本文讨论了在当前实验条件下该方案的可行性.

A scheme is proposed for deterministically implementing a controlled-phase flip gate with multi-target logic qubits via the input-output process of the cavity,in which two atoms are trapped and encoded as one logic qubit in the decoherence-free subspace.The scheme is not only robust against the collective dephasing errors,but also easy to implement.The analysis of fidelity for this gate shows the robustness to cavity decay.Under a medium coupling strength it reaches a high fidelity near unity.The discussion on experiment shows its feasibility with current technology.