论文标题
被动超导循环器在芯片上
Passive superconducting circulator on a chip
论文作者
论文摘要
与超导器件兼容的片上微波循环器是扩展超导电路的关键要素。在芯片上集成循环器的先前方法涉及需要额外的微波线的外部驾驶，或者需要损害超导性的强磁场。在这里，我们报告了一个被动芯片循环器的首次原理实现，该芯片循环器是由由三个概念相同的约瑟夫森连接中断的超导环制成的，仅通过DC控制场进行调整。我们的实验结果显示了非偏射散射的证据，并与理论模拟有着极好的一致性。我们还使用隐藏的马尔可夫模型对设备中的准粒子隧道进行了详细分析。通过降低连接不对称并利用已知的对准颗粒保护方法，我们预计约瑟夫森 - 环循环器将在超导电路中无处不在。
An on-chip microwave circulator that is compatible with superconducting devices is a key element for scale-up of superconducting circuits. Previous approaches to integrating circulators on chip involve either external driving that requires extra microwave lines or a strong magnetic field that would compromise superconductivity. Here we report the first proof-of-principle realisation of a passive on-chip circulator which is made from a superconducting loop interrupted by three notionally-identical Josephson junctions and is tuned with only DC control fields. Our experimental results shows evidence for nonreciprocal scattering, and excellent agreement with theoretical simulations. We also present a detailed analysis of quasiparticle tunneling in our device using a hidden Markov model. By reducing the junction asymmetry and utilising the known methods of protection from quasiparticles, we anticipate that Josephson-loop circulator will become ubiquitous in superconducting circuits.
