自差分交流偏置超导纳米线单光子探测器  

Superconducting nanowire single photon detector under AC-bias with self-differential readout

作　　者：马璐瑶 张兴雨 舒志运 肖游 张天柱 李浩[1,2] 尤立星 Ma Lu-Yao;Zhang Xing-Yu;Shu Zhi-Yun;Xiao You;Zhang Tian-Zhu;Li Hao;You Li-Xing(State Key Laboratory of Functional Materials for Informatics,Shanghai Institute of Microsystem and Information Technology,Chinese Academy of Sciences,Shanghai 200050,China;University of Chinese Academy of Sciences,Beijing 100039,China)

机构地区：[1]中国科学院上海微系统与信息技术研究所,信息功能材料国家重点实验室,上海200050 [2]中国科学院大学,北京100039

出　　处：《物理学报》2022年第15期281-287,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61971408,61827823);国家重点研发计划(批准号:2017YFA0304000);上海市市级科技重大专项(批准号:2019SHZDZX01);上海市青年科技启明星项目(批准号:20QA1410900);中国科学院青年创新促进会项目(批准号:2020241);浙江省级重点研发计划(批准号:2021C01188)资助的课题。

摘　　要：超导纳米线单光子探测器(SNSPD)因其优异的综合性能,在量子信息、激光雷达等方面有广泛的应用.通常,SNSPD工作在直流偏置下,在时域上具有自由运行探测的优点.而在卫星激光测距、单光子激光雷达等光信号到达时间有规律的应用场景中,使用交流偏置有望提升器件运行速率、有效抑制背景暗计数,却存在信号读出困难的棘手问题.本文报道了自差分读出的交流偏置SNSPD系统,该系统包含两根并行排布纳米线构成的2-pixel SNSPD器件.给两根纳米线加载相同的100 MHz交流偏置信号,并对两路输出信号差分使噪声信号相抵消,实现光子响应信号的读出.基于该方法测得,响应信号的信噪比相比差分之前提升10倍,在交流偏置下器件的暗计数降低至直流偏置下的约1/4,计数率达到直流偏置下的约1.5倍.本文为交流偏置SNSPD测试提供了一种思路,为其应用提供参考数据.Superconducting nanowire single photon detector(SNSPD) has been widely used in many fields such as quantum computing,quantum key distribution and laser radar,due to its high detection efficiency,low dark count rate,high counting rate,and low timing jitter.In most cases,the SNSPD works under the DC-bias mode that can detect single photons arrived at any time.In some cases such as satellite laser ranging and singlephoton laser radar where the light pulses arrive regularly,the AC-bias mode enables the SNSPD to work with higher counting rates and lower background dark counts,which however requires complicated readout due to the low signal-to-noise ratio of the photon response.In this work,we report on an AC-biased SNSPD system with a self-differential readout circuit.The system includes a 2-pixel SNSPD consisting of two parallel nanowires,which are biased with 100 MHz sinusoidal current.The output signals of these two nanowires are amplified and combined for the differential readout of the photon response.The resulting response pulse possesses a signal-to-noise ratio ten times higher than that extracted before self-differential readout.In addition,the dark counts are reduced by a factor of 4,and the count rates are increased by a factor of 1.5,in comparison with those under the DC-bias mode.This work provides a specific method to read out the AC-biased SNSPD.

关 键 词：超导纳米线单光子探测器 交流偏置 自差分读出 

分 类 号：TN256[电子电信—物理电子学]