论文标题
通过最佳控制，快速超导Qubit门的泄漏减少
Leakage reduction in fast superconducting qubit gates via optimal control
论文作者
论文摘要
达到高速，高富达量子量操作需要精确控制基础脉冲的形状。对于弱的静脉系统（例如超导式矩形Qub），短门会导致计算子空间之外的状态泄漏。使用开环最佳控制设计的控制脉冲可以减少这种泄漏。但是，模型不准确可以严重限制此类脉冲的可用性。我们实施了一个闭环优化，该优化同时根据Clifford Gates构建的成本函数的测量来同时调整所有控制参数。通过使用与控制硬件的能力匹配的分段组分表示脉冲，我们创建了一个$ 4.16〜 \ rm {ns} $单点脉冲，其单点脉冲，$ 99.76 \，\％$ $ $ fidelity和$ 0.044 \，\％\，\％$ $漏洞。这是我们在同一系统上如此短的持续时间进行校准的最佳阻力脉冲的泄漏率降低了七倍。
Reaching high speed, high fidelity qubit operations requires precise control over the shape of the underlying pulses. For weakly anharmonic systems, such as superconducting transmon qubits, short gates lead to leakage to states outside of the computational subspace. Control pulses designed with open-loop optimal control may reduce such leakage. However, model inaccuracies can severely limit the usability of such pulses. We implemented a closed-loop optimization that simultaneously adapts all control parameters based on measurements of a cost function built from Clifford gates. By parameterizing pulses with a piecewise-constant representation that matches the capabilities of the control hardware we create a $4.16~\rm{ns}$ single-qubit pulse with $99.76\,\%$ fidelity and $0.044\,\%$ leakage. This is a seven-fold reduction of the leakage rate of the best DRAG pulse we have calibrated at such short durations on the same system.
