论文标题
与低频保护超导码头的纠缠transmon
Entangling transmons with low-frequency protected superconducting qubits
论文作者
论文摘要
具有内在噪声保护的新量子位是改善超导电路中量子信息连贯性的有希望的途径。然而，许多受保护的超导量子位表现出相对较低的过渡频率，这可能会使它们与常规的Transmon电路构成具有挑战性。在这项工作中，我们提出并研究了一种将可调节的transmon与库珀对偶数保护的量子纠缠的方案，这是低频保护量子的范式示例，该量子在超导岛上的相对库珀平价状态下存储量子信息。通过调整Transmon上的外部通量，我们表明非计算状态可以介导一个两倍的纠缠栅极，该门可以保留库珀对奇偶校验，而与详细的脉冲序列无关。有趣的是，纠缠的门与传统的transmon设备中的受控相位门具有相似之处。因此，我们的结果表明，可以重新使用标准的高精度门校准协议，以用于操作混合量子设备。
Novel qubits with intrinsic noise protection constitute a promising route for improving the coherence of quantum information in superconducting circuits. However, many protected superconducting qubits exhibit relatively low transition frequencies, which could make their integration with conventional transmon circuits challenging. In this work, we propose and study a scheme for entangling a tunable transmon with a Cooper-pair parity-protected qubit, a paradigmatic example of a low-frequency protected qubit that stores quantum information in opposite Cooper-pair parity states on a superconducting island. By tuning the external flux on the transmon, we show that non-computational states can mediate a two-qubit entangling gate that preserves the Cooper-pair parity independent of the detailed pulse sequence. Interestingly, the entangling gate bears similarities to a controlled-phase gate in conventional transmon devices. Hence, our results suggest that standard high-precision gate calibration protocols could be repurposed for operating hybrid qubit devices.
