Breaking the trade-off between fast control and long lifetime of a superconducting qubit
Breaking the trade-off between fast control and long lifetime of a superconducting qubit
复制标题
DOI：
10.1038/s41467-020-17511-y
复制
发表时间：
2020-07-23
影响因子：
16.6
通讯作者：
Nakamura, Y.
中科院分区：
文献类型：
--
作者：
Kono, S.;Koshino, K.;Nakamura, Y.
超导量子位设计和制造技术的快速发展使得量子位的相干时间更长。然而，在未来，量子位进入其控制线的辐射衰变将成为一个基本限制，需要在量子位的快速控制和长寿命之间进行权衡。在这里，我们通过沿控制线强耦合另一个超导量子位来打破这种权衡。第二个量子位，我们称之为“约瑟夫森量子滤波器”（JQF），可防止第一个量子位发射微波光子，从而抑制其弛豫，同时由于量子滤波器的饱和而传输大振幅控制微波脉冲，从而实现快速量子位控制。该设备充当量子位与其控制线之间的自动解耦器，可以通过减少量子位环境的发热和量子位之间的串扰来帮助实现大规模超导量子处理器。
The rapid development in designs and fabrication techniques of superconducting qubits has made coherence times of qubits longer. In the future, however, the radiative decay of a qubit into its control line will be a fundamental limitation, imposing a trade-off between fast control and long lifetime of the qubit. Here, we break this trade-off by strongly coupling another superconducting qubit along the control line. This second qubit, which we call "Josephson quantum filter" (JQF), prevents the first qubit from emitting microwave photons and thus suppresses its relaxation, while transmitting large-amplitude control microwave pulses due to the saturation of the quantum filter, enabling fast qubit control. This device functions as an automatic decoupler between a qubit and its control line and could help in the realization of a large-scale superconducting quantum processor by reducing the heating of the qubit environment and the crosstalk between qubits.