论文标题
在被困的离子量子计算机中单独解决的两倍大门中的串扰抑制
Crosstalk Suppression in Individually Addressed Two-Qubit Gates in a Trapped-Ion Quantum Computer
论文作者
论文摘要
由于控制信号的溢出而导致的目标和相邻观众量子位之间的串扰代表了一个主要的误差源，限制了量子计算机中两倍纠缠大门的保真度。我们表明，在激光驱动的捕获 - 离子系统中，连贯的串扰误差可以建模为残留$ x \ hatσ_ϕ $相互作用，并且可以通过单Qubit Echo的脉冲来积极取消。我们提出并演示了一种消除所有一阶串扰的串扰抑制方案，但仅通过仅在目标码头上驱动旋转才需要局部控制。我们报告的是，在集体大门之后使用的回声脉冲和$ 99.37（5）\％$的回声脉冲，在5-ION链中应用的回声脉冲。该方案广泛适用于具有类似相互作用的哈密顿人的其他平台。
Crosstalk between target and neighboring spectator qubits due to spillover of control signals represents a major error source limiting the fidelity of two-qubit entangling gates in quantum computers. We show that in our laser-driven trapped-ion system coherent crosstalk error can be modelled as residual $X\hatσ_ϕ$ interaction and can be actively cancelled by single-qubit echoing pulses. We propose and demonstrate a crosstalk suppression scheme that eliminates all first-order crosstalk, yet only requires local control by driving rotations solely on the target qubits. We report a two-qubit Bell state fidelity of $99.52(6) \%$ with the echoing pulses applied after collective gates and $99.37(5) \%$ with the echoing pulses applied to each gate in a 5-ion chain. This scheme is widely applicable to other platforms with analogous interaction Hamiltonians.
