采用深紫外兼容双层光栅的单孔径双色离子寻址

中文摘要 AI 辅助

多波长光学控制是囚禁离子硬件的一个缩放瓶颈：单独的表面发射器会占用阱区域、中断电极平面，并使离子附近的电荷敏感电介质暴露。本文中，垂直堆叠的氮化硅双层将40Ca+量子比特和再泵浦场（729.4和854.2纳米）通过一个电极孔径传输，并将它们聚焦在芯片上方70微米处。三维FDTDX预测颜色分离为0.10微米，且沿离子链轴的光斑接近衍射极限。多级深度分配变迹通过在离散蚀刻层而非亚分辨率线宽中编码耦合包络来实现这种架构。每个特征都满足严格的≥125纳米深紫外规则，每层使用两种蚀刻深度。全3D Ansys Lumerical模拟独立证实了方向性、光斑尺寸和再泵浦效率。在常见的50纳米报告网格上，深紫外兼容器件在量子比特通道上与63纳米电子束设计相匹配（聚焦效率0.286对0.288；串扰-24.0对-24.3分贝）。垂直集成因此将波长缩放从横向占用惩罚转换为层分配问题，为囚禁离子和其他芯片寻址量子发射器的紧凑型多色光子接口提供了一条途径。

英文摘要

Scaling multicolor quantum control on chip presents a geometric conflict: each added wavelength traditionally requires another routing corridor, emitter, and electrode opening, consuming trap-surface area and exposing charge-susceptible dielectric near the quantum target. This work introduces an all-planar, vertically stacked silicon-nitride architecture that co-registers independently fed optical transitions within one 24 x 24 $μ$m footprint. For $^{40}\text{Ca}^+$, the device focuses the 729.4 nm qubit and 854.2 nm repump wavelengths onto a shared site 70 $μ$m above the upper film. A hierarchical design combines a differentiable cell search for a three-level scatterer, analytic confocal phase synthesis, and deterministic depth allocation across two etches per layer, preserving an explicit 125 nm propagation-axis line-and-space floor without grayscale patterning. Retargeting the upper-layer phase co-registers the focal maxima to within 0.1 $μ$m in mesh-converged Tidy3D and independently constructed Lumerical FDTD models, retaining >99.9% of each color's peak intensity at the common coordinate with focusing efficiencies of 0.410 and 0.168. At 5 $μ$m ion spacing, the qubit channel reaches -24.8 dB point crosstalk, remains below -18.0 dB across a 0.5 $μ$m-radius positioning disk, and yields -23.0 dB symmetric-traceless field-gradient suppression. In the analytic House conductor geometry, the shared footprint provides 15.3 $μ$m clearance to the nearest radio-frequency rail with zero RF-null displacement. By uniting separate optical inputs and transition-specific wavefronts within one ion-facing aperture, this hierarchy establishes a transferable template for addressing other atomic wavelength pairs and dense multicolor quantum interfaces.

发表机构

• Centre for Quantum Technologies, National University of Singapore（新加坡国立大学量子技术中心）

机构由 AI 辅助整理，请以论文原文为准。