Ultimate performance of a superconducting quantum detector
Ultimate performance of a superconducting quantum detector
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DOI：
10.1051/epjap:2003009
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发表时间：
2003-03-01
影响因子：
1
通讯作者：
Hübers, HW
中科院分区：
文献类型：
--
作者：
Semenov, A;Engel, A;Hübers, HW
我们分析了超导量子探测器的最终性能，以满足近红外天文学和X射线光谱学应用的要求。该探测器利用了一种组合的检测机制，其中雪崩准粒子倍增和超电流通过在窄超导条中连续形成光子诱导和电流诱导的正常热点来联合产生对单个吸收光子的电压响应。探测器的响应时间应该随着提供能量分辨率的光子能量而增加。根据超导材料和操作条件，单光子探测机制的截止波长从红外波到可见光不等。利用上述机制，我们模拟了背景限制红外直接探测器和X射线光子计数器的性能。低暗计数率和固有的低频截止允许对于暴露于4-K背景辐射的远红外直接检测器实现10（-20）WHz（-1/2）的背景限制噪声等效功率。在低温下，计数器的本征响应时间是由非平衡电子的扩散而不是由能量转移到声子的速率决定的。因此，热波动不会妨碍X射线光子计数器的能量分辨率，其对于6 keV光子应该优于10（-3）。新的数据与铌基探测器和以前报道的结果NbN量子探测器的比较支持我们的估计最终检测器的性能。
We analyze the ultimate performance of a superconducting quantum detector in order to meet requirements for applications in near-infrared astronomy and X-ray spectroscopy. The detector exploits a combined detection mechanism, in which avalanche quasiparticle multiplication and the supercurrent jointly produce a voltage response to a single absorbed photon via successive formation of a photon-induced and a current-induced normal hotspot in a narrow superconducting strip. The response time of the detector should increase with the photon energy providing energy resolution. Depending on the superconducting material and operation conditions, the cut-off wavelength for the single-photon detection regime varies from infrared waves to visible light. We simulated the performance of the background-limited infrared direct detector and X-ray photon counter utilizing the above mechanism. Low dark count rate and intrinsic low-frequency cut-off allow for realizing a background limited noise equivalent power of 10(-20) WHz(-1/2) for a far-infrared direct detector exposed to 4-K background radiation. At low temperatures, the intrinsic response time of the counter is rather determined by diffusion of nonequilibrium electrons than by the rate of energy transfer to phonons. Therefore, thermal fluctuations do not hamper energy resolution of the X-ray photon counter that should be better than 10(-3) for 6-keV photons. Comparison of new data obtained with a Nb based detector and previously reported results on NbN quantum detectors support our estimates of ultimate detector performance.