Evolution of Nanowire Transmon Qubits and Their Coherence in a Magnetic Field
Evolution of Nanowire Transmon Qubits and Their Coherence in a Magnetic Field
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DOI：
10.1103/physrevlett.120.100502
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发表时间：
2018-03-09
影响因子：
8.6
通讯作者：
DiCarlo, L.
中科院分区：
文献类型：
--
作者：
Luthi, F.;Stavenga, T.;DiCarlo, L.
我们提出了一个实验研究的通量和栅极可调纳米线transmons与国家的最先进的弛豫时间允许定量提取通量和电荷噪声耦合到约瑟夫森能量。我们的证据的连贯性甜蜜点的电荷，调整的近端侧栅极上的电压，其中一阶灵敏度切换两个级别的系统和背景1 / f噪声最小化。接下来，我们研究了纳米线transmon在平行磁场中的演变高达70 mT，上限设置的感应间隙的关闭。在量子比特能量弛豫和退相时间的场依赖性中观察到的几个特征还没有完全理解。使用具有较薄的部分覆盖的Al壳的纳米线将使这些电路的操作高达0.5 T，这是与拓扑量子计算和其他应用相关的制度。
We present an experimental study of flux- and gate-tunable nanowire transmons with state-of-the-art relaxation time allowing quantitative extraction of flux and charge noise coupling to the Josephson energy. We evidence coherence sweet spots for charge, tuned by voltage on a proximal side gate, where first order sensitivity to switching two-level systems and background 1 / f noise is minimized. Next, we investigate the evolution of a nanowire transmon in a parallel magnetic field up to 70 mT, the upper bound set by the closing of the induced gap. Several features observed in the field dependence of qubit energy relaxation and dephasing times are not fully understood. Using nanowires with a thinner, partially covering Al shell will enable operation of these circuits up to 0.5 T, a regime relevant for topological quantum computation and other applications.