近日，英国牛津大学的Christopher J. Ballance&Martin J. Booth及其研究团队取得一项新进展。经过不懈努力，他们利用一种新型集成光子芯片实现捕获离子量子比特的低串扰寻址。相关研究成果已于2024年8月20日在国际知名学术期刊《光：科学与应用》上发表。

该研究团队提出一种可扩展的方法，通过使用与光纤组件网络连接的高性能集成光子芯片来实现所有这些功能。该芯片设计通过在通道芯和包层之间实现非常高的折射率对比度，即使在微米级间距下也能使相邻通道之间的串扰非常低。

此外，光子芯片的制造工艺具有高度的灵活性，可以制造具有任意数量通道以及芯片输出处非均匀通道间距的器件。研究人员展示了将芯片集成到离子阱装置中所使用的系统，并使用单个捕获离子作为光场传感器来表征完整单个寻址设置的性能。这项测量结果显示，整个芯片的强度串扰低于10^-3，观察到的最小串扰低至10^-5。

据悉，在捕获的原子离子链中进行单个光学寻址需要生成许多小且间隔紧密的光束，且这些光束之间的串扰要低。此外，实现并行操作需要对每个单独光束的相位、频率和幅度进行控制。

附：英文原文

Title: Low cross-talk optical addressing of trapped-ion qubits using a novel integrated photonic chip

Author: Sotirova, Ana S., Sun, Bangshan, Leppard, Jamie D., Wang, Andong, Wang, Mohan, Vazquez-Brennan, Andres, Nadlinger, David P., Moser, Simon, Jesacher, Alexander, He, Chao, Pokorny, Fabian, Booth, Martin J., Ballance, Christopher J.

Issue&Volume: 2024-08-20

Abstract: Individual optical addressing in chains of trapped atomic ions requires the generation of many small, closely spaced beams with low cross-talk. Furthermore, implementing parallel operations necessitates phase, frequency, and amplitude control of each individual beam. Here, we present a scalable method for achieving all of these capabilities using a high-performance integrated photonic chip coupled to a network of optical fibre components. The chip design results in very low cross-talk between neighbouring channels even at the micrometre-scale spacing by implementing a very high refractive index contrast between the channel core and cladding. Furthermore, the photonic chip manufacturing procedure is highly flexible, allowing for the creation of devices with an arbitrary number of channels as well as non-uniform channel spacing at the chip output. We present the system used to integrate the chip within our ion trap apparatus and characterise the performance of the full individual addressing setup using a single trapped ion as a light-field sensor. Our measurements showed intensity cross-talk below ~10^–3 across the chip, with minimum observed cross-talk as low as ~10^–5.

DOI: 10.1038/s41377-024-01542-x

Source: https://www.nature.com/articles/s41377-024-01542-x