论文标题
避免由Lambda系统中不需要的过渡引起的泄漏和错误
Avoiding leakage and errors caused by unwanted transitions in Lambda systems
论文作者
论文摘要
三级Lambda系统出现在各种量子信息处理平台中。在几种控制方案中，激发级是用于在较低Qubit状态之间实现门操作的辅助状态。但是，额外的激发水平会导致不良的过渡，导致泄漏和其他错误，从而降低了门的保真度。我们专注于针对门口和设计协议的连贯人口捕获方案，该方案减少了不需要的偏置耦合的影响，并将门的性能提高到几个数量级。对于特定不需要的耦合的特定设置，我们找到了一个精确的解决方案，该解决方案仅通过静态失调修改导致无错误的门操作。在一般情况下，我们通过向脉冲添加纠正式调制来改善门操作，从而将阻力协议推广到lambda系统。我们的技术实现了快速和高保真的大门，并应用于多种光学驱动的平台，例如量子点，颜色中心和被困的离子。
Three-level Lambda systems appear in various quantum information processing platforms. In several control schemes, the excited level serves as an auxiliary state for implementing gate operations between the lower qubit states. However, extra excited levels give rise to unwanted transitions that cause leakage and other errors, degrading the gate fidelity. We focus on a coherent-population-trapping scheme for gates and design protocols that reduce the effects of the unwanted off-resonant couplings and improve the gate performance up to several orders of magnitude. For a particular setup of unwanted couplings, we find an exact solution, which leads to error-free gate operations via only a static detuning modification. In the general case, we improve gate operations by adding corrective modulations to the pulses, thereby generalizing the DRAG protocol to Lambda systems. Our techniques enable fast and high-fidelity gates and apply to a wide range of optically driven platforms, such as quantum dots, color centers, and trapped ions.
