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Photon number resolvability of multi-pixel superconducting nanowire single photon detectors using a single flux quantum circuit 下载免费PDF全文
Hou-Rong Zhou 《中国物理 B》2022,31(5):57401-057401
Superconducting nanowire single-photon detectors (SNSPDs) are typical switching devices capable of detecting single photons with almost 100% detection efficiency. However, they cannot determine the exact number of incident photons during a detection event. Multi-pixel SNSPDs employing multiple read-out channels can provide photon number resolvability (PNR), but they require increased cooling power and costly multi-channel electronic systems. In this work, a single-flux quantum (SFQ) circuit is employed, and PNR based on multi-pixel SNSPDs is successfully demonstrated. A multi-input magnetically coupled DC/SFQ converter (MMD2Q) circuit with a mutual inductance M is used to combine and record signals from a multi-pixel SNSPD device. The designed circuit is capable of discriminating the amplitude of the combined signals in accuracy of Φ0/M with Φ0 being a single magnetic flux quantum. By employing the MMD2Q circuit, the discrimination of up to 40 photons can be simulated. A 4-parallel-input MMD2Q circuit is fabricated, and a PNR of 3 is successfully demonstrated for an SNSPD array with one channel reserved for the functional verification. The results confirm that an MMD2Q circuit is an effective tool for implementing PNR with multi-pixel SNSPDs. 相似文献
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高温超导薄膜的微波性能受制备工艺和衬底材料性能的影响,常常出现空间不均匀分布,因此,无损检测大面积超导薄膜及衬底材料的微波性能,研究影响局域微波性能的因素,是高温超导微波器件应用研究中的一个重要方面.我们设计和制造了一套同轴谐振腔型微波近场扫描显微镜,利用该显微镜研究了金属薄膜样品微波表面电阻和介质材料的介电常数的空间分布,给出了其空间分辨率并分析了影响空间分辨率的因素.利用这套微波近场扫描显微镜,对大面积LaAlO3单晶衬底材料介电常数的空间分布进行了测量,并分析了其测量精度.最后,利用这套微波近场扫描显微镜,研究了YBaCuO薄膜平面微波器件的微波表面电阻的分布情况,对影响其局域微波性能的因素做了初步分析 相似文献
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Fabrication and characterization of on-chip silicon spherical-like microcavities with high Q-factors
An effective way to fabricate high-quality (Q) silicon microcavities on-chip is proposed and studied.Our fabrication technique consists of two significant steps:(1) patterning a special silicon micro-pillar by Bosch processes and (2) subsequent reflow of the pillar into a spherical-like microcavity using a laser pulse at 532 nm.Its shape and surface roughness are characterized using a scanning electron microscope and an atomic force microscope.The root-mean-square roughness of the surface is abo... 相似文献
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The vortex pinning determining the current carrying capacity of a superconductor is an important property to the applications of superconducting materials.For layered superconductors,the vortex pinning can be enhanced by a strong interlayer interaction in accompany with a suppression of superconducting anisotropy,which remains to be investigated in iron based superconductors(FeSCs)with the layered structure.Here,based on the transport and magnetic torque measurements,we experimentally investigate the vortex pinning in two bilayer FeSCs,CaKFe4As4(Fe1144)and KCa2Fe4As4F2(Fe12442),and compare their superconducting anisotropyγ.While the anisotropyγ≈3 for Fe1144 is much smaller thanγ≈15 in Fe12442 around Tc,a higher flux pinning energy as evidenced by a higher critical current density is found in Fe1144,as compared with the case of Fe12442.In combination with the literature data of Ba0.72K0.28Fe2As2 and Nd Fe AsO0.82F0.18,we reveal an anti-correlation between the pinning energy and the superconducting anisotropy in these Fe SCs.Our results thus suggest that the interlayer interaction can not be neglected when considering the vortex pinning in Fe SCs. 相似文献
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A Silicon Shallow-Ridge Waveguide Integrated Superconducting Nanowire Single Photon Detector Towards Quantum Photonic Circuits 下载免费PDF全文
A silicon shallow-ridge waveguide integrated superconducting nanowire single photon detector is designed and fabricated.At the bias current of 11.6μA,4% on-chip detection efficiency near 1550 nm wavelength is achieved with the dark count rate of 3 Hz and a timing jitter of 75 ps.This device shows the potential application in the integration of superconducting nanowire single photon detectors with a complex quantum photonic circuit. 相似文献
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Photon-counting chirped amplitude modulation lidar system using superconducting nanowire single-photon detector at 1550-nm wavelength 下载免费PDF全文
We demonstrate a photon-counting chirped amplitude modulation(CAM) light detection and ranging(lidar) system incorporating a superconducting nanowire single-photon detector(SNSPD) and operated at a wavelength of 1550 nm.The distance accuracy of the lidar system was determined by the CAM bandwidth and signal-to-noise ratio(SNR) of an intermediate frequency(IF) signal. Owing to a short dead time(10 ns) and negligible dark count rate(70 Hz) of the SNSPD, the obtained IF signal attained an SNR of 42 d B and the direct distance accuracy was improved to 3 mm when the modulation bandwidth of the CAM signal was 240 MHz and the modulation period was 1 ms. 相似文献
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超导纳米线单光子探测器(SNSPD)作为一种新型的单光子探测器,相比于传统半导体或超导单光子探测器,具有高探测效率、低暗计数率、低时间抖动、高计数率和宽谱响应等优势.这使其可以应用于诸多领域,如量子通信、量子光源表征、激光测距、成像雷达等.本文将对SNSPD做一个简单的介绍,并着重介绍SNSPD在成像方面的应用进展,主... 相似文献
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利用超导宏观量子效应与环境电磁场的相互作用,超导探测器可以实现量子极限灵敏度探测。超导纳米线单光子探测器(SNSPD)具备高探测效率、低暗计数等优异的性能,已经在量子信息、深空通信、激光雷达等领域得到了广泛的应用,并为中国“九章”光量子计算原型机、量子密钥分发等领域达到国际领先水平提供了核心探测技术支持。文章简述了SNSPD的基本原理,对其性能、制冷技术、应用以及常见的问题等进行了介绍,并对未来发展做了展望。 相似文献