标题： 少层NbSe$_2$超导纳米线中的单光子检测 显示英文标题

标题： Single-Photon Detection in Few-Layer NbSe$_2$ Superconducting Nanowires

摘要： 超导纳米线单光子探测器（SNSPDs）由于能够以超高效率、低暗计数和快速时间分辨率检测单个光子，是光子量子技术的关键构建模块。 具有高均匀性、大吸收截面和原子级厚度的超导材料对于将单光子检测从近红外扩展到太赫兹范围至关重要，因为在该范围内现有的材料选择尤其受限。 基底独立性将进一步使探测器集成到功能材料和异质结构上，从而提高性能并实现对各种单独激发的邻近读出。 在此，我们自上而下地将典型的二维超导体二硒化铌（NbSe$_2$）制成宽度小于100 nm的少层纳米线，并在780 nm和1550 nm波长下实现了单光子检测。 同时，暗计数率在切换电流下仍保持低于1 Hz，并实现了低于50 ps的时间抖动。 我们使用扩散热点模型估计了一个理论截止波长，该波长超过了毫米波范围。 我们的结果为集成到量子光子电路和量子器件中的量子极限探测器开辟了道路，具有新型检测能力和前所未有的能量灵敏度的潜力。 显示英文摘要

摘要： Superconducting Nanowire Single-Photon Detectors (SNSPDs) are key building blocks for photonic quantum technologies due to their ability to detect single photons with ultra-high efficiency, low dark counts and fast temporal resolution. Superconducting materials exhibiting high uniformity, large absorption cross-section and atomic-scale thickness are desirable to extend single-photon detection from the near-infrared up to the terahertz regime, where existing material choices are especially constrained. Substrate independence would further open the way to integrate detectors onto functional materials and heterostructures, enhancing performance and enabling proximal read-out of a wide range of individual excitations. Here, we top-down shape the prototypical two-dimensional superconductor niobium diselenide (NbSe$_2$) into few-layer nanowires less than 100 nm wide and demonstrate single-photon detection at 780 and 1550 nm. At the same time, the dark-count rate remains below 1 Hz up to the switching current and we achieve a timing jitter below 50 ps. We use a diffusive hot-spot model to estimate a theoretical cut-off wavelength that surpasses the millimetre range. Our results open up routes toward quantum limited detectors integrated into quantum-photonic circuits and quantum devices, with the potential for novel detection capabilities and unprecedented energy sensitivity.