论文标题
强大的纠缠大门，用于电容性耦合的几个电子旋风 - 三刺Qubits
Robust entangling gate for capacitively coupled few-electron singlet-triplet qubits
论文作者
论文摘要
搜索量子控制对噪声一阶不敏感的量子参数中的最佳点，是实现高保真量子门的关键。在传统的双量子点单线刺激器中搜索如此甜蜜的努力，其中每个点都有一个电子（“两电子单曲 - 怪物量子量”），尤其是对于两个Qubit的操作，都没有成功。在这里，我们考虑允许每个点托管一个以上电子的单线量子量子尺，在双量子点中总共有四个电子（“四电子单曲 - 三个怪物”）。从理论上讲，我们使用配置交流计算来证明甜点出现在此耦合量子系统中。我们进一步证明，在逼真的电荷噪声和超细噪声下，在拟议的最佳命中率的两分点操作可以提供高于传统的两电子单元 - 三键式Qubit System（$ \ sim90 \％$ $）的门贴（$ \ sim99 \％$）。我们的结果应促进在单线量子Qubit System中实现高保真性两分之二门的实现。
The search of a sweet spot, locus in qubit parameters where quantum control is first-order insensitive to noises, is key to achieve high-fidelity quantum gates. Efforts to search for such a sweet spot in conventional double-quantum-dot singlet-triplet qubits where each dot hosts one electron ("two-electron singlet-triplet qubit"), especially for two-qubit operations, have been unsuccessful. Here we consider singlet-triplet qubits allowing each dot to host more than one electron, with a total of four electrons in the double quantum dots ("four-electron singlet-triplet qubit"). We theoretically demonstrate, using configuration-interaction calculations, that sweet spots appear in this coupled qubit system. We further demonstrate that, under realistic charge noise and hyperfine noise, two-qubit operation at the proposed sweet spot could offer gate fidelities ($\sim99\%$) that are higher than conventional two-electron singlet-triplet qubit system ($\sim90\%$). Our results should facilitate realization of high-fidelity two-qubit gates in singlet-triplet qubit systems.
