标题： 使用轴向运动模式在被捕获的离子链中实现高保真度的两量子比特量子逻辑门 显示英文标题

标题： High-fidelity two-qubit quantum logic gates in a trapped-ion chain using axial motional modes

摘要： 囚禁离子系统是量子信息处理的主要平台之一，其中关键挑战是在扩大系统规模的同时保持高保真度的两量子比特操作。 一种有前景的方法是通过强耦合互连构建高性能模块。 特别是，轴向运动模式为耦合短离子链提供了一种可行的方法。 然而，基于轴向模式的全连接5离子模块之前的实现仅限于保真度为$96.6-98.0\%$。 在这里，我们使用轴向模式在5离子$^{40}$Ca$^{+}$链中演示了两量子比特量子逻辑门，通过仔细处理主要的误差源，实现了相邻对的保真度超过$99\%$，任意对的保真度超过$98\%$。 我们的结果有助于可扩展离子阱量子处理器、量子模拟和量子增强计量的发展。 显示英文摘要

摘要： Trapped-ion systems are one of the leading platforms for quantum information processing, where a key challenge is to scale up system size while maintaining high-fidelity two-qubit operations. A promising approach is to build high-performance modules interconnected via strong coupling. In particular, axial motional modes provide a feasible means of coupling short ion chains. However, previous implementations of fully connected 5-ion modules based on axial modes have been limited to fidelities of $96.6-98.0\%$. Here, we demonstrate two-qubit quantum logic gates in a 5-ion $^{40}$Ca$^{+}$ chain using axial modes, achieving fidelities exceeding $99\%$ for adjacent pairs and over $98\%$ for arbitrary pairs by carefully tackling dominant error sources. Our results are beneficial to the development of scalable ion-trap quantum processors, quantum simulation and quantum-enhanced metrology.