Nonexponential fidelity decay in randomized benchmarking with low-frequency noise
Nonexponential fidelity decay in randomized benchmarking with low-frequency noise
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DOI：
10.1103/physreva.92.022326
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发表时间：
2015-08-11
影响因子：
2.9
通讯作者：
Dzurak, A. S.
中科院分区：
文献类型：
--
作者：
Fogarty, M. A.;Veldhorst, M.;Dzurak, A. S.
我们证明了在量子点量子比特的随机基准实验中，非指数保真度的衰减与包含低频噪声的数值模拟是一致的，并且对应于随时间缓慢变化的控制保真度。通过将标准的随机基准分析扩展到这个实验区域，我们发现这种非指数衰变可以更好地用多个指数衰减率来模拟，导致同位素提纯的硅金属氧化物半导体量子点量子比特的瞬时控制保真度在低频噪声引起大失谐时为98.9%，但当量子比特被共振驱动并且系统校准良好时，可以高达99.9%。这些在量子比特表征和验证方法方面的进展支持了硅作为容错量子计算的量子比特平台的可观前景。
We show that nonexponential fidelity decays in randomized benchmarking experiments on quantum-dot qubits are consistent with numerical simulations that incorporate low-frequency noise and correspond to a control fidelity that varies slowly with time. By expanding standard randomized benchmarking analysis to this experimental regime, we find that such nonexponential decays are better modeled by multiple exponential decay rates, leading to an instantaneous control fidelity for isotopically purified silicon metal-oxide-semiconductor quantum-dot qubits which is 98.9% when the low-frequency noise causes large detuning but can be as high as 99.9% when the qubit is driven on resonance and system calibrations are favorable. These advances in qubit characterization and validation methods underpin the considerable prospects for silicon as a qubit platform for fault-tolerant quantum computation.