AI 中文总结
该研究提出利用两个匹配的氮化硅微环，通过片上量子测量方案观测到4.6 dB量子噪声降低，实现了首个单片SU(1,1)干涉仪，为芯片量子传感器提供实用路径。
AI 中文摘要
量子光学技术的片上集成对量子技术的大规模应用至关重要，这类技术在自由空间环境中已被证实优于对应的经典技术。光的压缩态可用于提升量子传感器的灵敏度和实现容错量子计算。尽管基于芯片的压缩光生成技术已取得显著进展，但其实用价值仍有限，因为芯片与片外探测器之间的耦合损耗会破坏脆弱的量子关联，限制观测到的压缩量。在此，我们借助参量放大器实现片上量子测量的思路，并将其应用于氮化硅（SiN）微环谐振器产生的压缩态，以克服这一限制。在我们的方案中，依次构建两个匹配的SiN微环：第一个微环生成压缩态，第二个微环作为高增益参量放大器（PA），在光经历显著片外损耗前对压缩态进行测量。该架构固有抗损耗特性：放大器将量子噪声提升至远高于真空能级，使测量对下游损耗不敏感。尽管芯片到光纤的耦合损耗超过5 dB，我们仍直接观测到第一个微环产生的4.6 dB量子噪声降低。本研究还展示了首个单片SU(1,1)干涉仪，其信噪比估计比传统线性干涉仪提升5 dB，从而为基于芯片的量子传感器确立了实用路径。
英文摘要
Integration of quantum optical technique on-chip is crucial for large scale applications of quantum technology, which were proven in a free space environment to be superior to the corresponding classical technology. Squeezed states of light can be used for enhancing the sensitivity of quantum sensors and for fault-tolerant quantum computing. Although chip-based squeezed light generation has advanced significantly, practical impact remains limited because coupling losses between the chip and off-chip detectors destroy delicate quantum correlations, restricting the amount of observed squeezing. Here, we overcome this limitation by implementing the idea of on-chip quantum measurement with the aid of a parametric amplifier and applying it to the squeezed state generated by a silicon nitride (SiN) microring resonator. In our scheme, two matched SiN micro-rings are sequentially constructed. The first ring generates a squeezed state, whereas the second ring acts as a high-gain parametric amplifier (PA) that measures the squeezed state before the light experiences significant off-chip loss. This architecture is inherently loss-tolerant: the amplifier elevates the quantum noise well above the vacuum level, making the measurement insensitive to downstream losses. We directly observe a quantum noise reduction of 4.6 dB from the first ring, despite a chip-to-fiber coupling loss exceeding 5 dB. This work also demonstrates the first monolithic SU(1,1) interferometer with an estimated 5 dB signal-to-noise enhancement compared to traditional linear interferometers, and thus establishes a practical pathway for chip-based quantum sensors.
Comments20 pages, 7 figures
