论文标题
使用双重汉密尔顿参数估计进行探测双线性策略以外的两数量电容式相互作用
Probing two-qubit capacitive interactions beyond bilinear regime using dual Hamiltonian parameter estimations
论文作者
论文摘要
我们报告了一对两电子旋转量子台的同时操作和两量子耦合测量值，这些旋转量子位在GAAS四倍量子点阵列中积极地与非准核噪声分离。通过使用快速收敛的实时汉密尔顿估计量来连续调整驱动频率，可以实现两个量子位（衰减时间$ \ $2μs;频率很少MHz）的连贯的Rabi振荡。根据国家条件交换的振荡测量，我们还观察到了强大的两数量电容相互作用（> 190 MHz）。我们表明，相对于标准内交换能的缩放比最近的理论预测一致。我们观察到一致性和条件相叉时间之间的高比率（> 16），这支持了使用简单的电容式相互作用在编码的自旋圆点之间产生高保真性和快速量子纠缠的可能性。
We report the simultaneous operation and two-qubit coupling measurement of a pair of two-electron spin qubits that are actively decoupled from quasistatic nuclear noise in a GaAs quadruple quantum dot array. Coherent Rabi oscillations of both qubits (decay time $\approx$2 μs; frequency few MHz) are achieved by continuously tuning the drive frequency using rapidly converging real-time Hamiltonian estimators. By state conditional exchange oscillation measurements, we also observe strong two-qubit capacitive interaction (> 190 MHz). We show that the scaling of the capacitive interaction with respect to intra-qubit exchange energies is stronger than the bilinear form, consistent with recent theoretical predictions. We observe a high ratio (>16) between coherence and conditional phase-flip time, which supports the possibility of generating high-fidelity and fast quantum entanglement between encoded spin qubits using a simple capacitive interaction.
