Different Single-Photon Response of Wide and Narrow Superconducting MoxSi1−x Strips
Different Single-Photon Response of Wide and Narrow Superconducting
MoxSi1−x
Strips
复制标题
宽窄超导 MoxSi1−x 条带的不同单光子响应
DOI：
10.1103/physrevapplied.13.024011
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发表时间：
2019
影响因子：
4.6
通讯作者：
D. Vodolazov
中科院分区：
文献类型：
--
作者：
Y. Korneeva;N. Manova;I. Florya;M. Mikhailov;O. Dobrovolskiy;A. Korneev;D. Vodolazov
通过实验研究了由 MoSi 薄膜制成的超导单光子探测器的光子计数率，该探测器的形状为 $2\,\mu$m 宽的条带和 115 nm 宽的曲折带状线，作为不同垂直磁场值下直流偏置电流的函数。对于宽条带，观察到交叉电流 $I_\textrm{cross}$，低于该电流，光子计数率随着磁场的增加而增加，高于该电流，则光子计数率降低。这种行为与没有观察到交叉电流的窄 MoSi 曲折形成鲜明对比，因此表明宽条和窄条中的光子检测机制不同。也就是说，我们认为，在宽条带中，吸收的光子通过涡流-反涡流机制局部破坏超导性，从而出现阻力，而在窄曲流中，整个带状线的超导性被破坏，形成热带。因此，与涡流和热带相关的不同光子检测机制规定了光子计数率对磁场的依赖性的质的差异。
The photon count rate of superconducting single photon detectors made of MoSi films shaped as a $2\,\mu$m-wide strip and a 115 nm-wide meander stripline is studied experimentally as a function of the dc biasing current at different values of the perpendicular magnetic field. For the wide strip a crossover current $I_\textrm{cross}$ is observed, below which the photon count rate increases with increasing magnetic field and above which it decreases. This behavior contrasts with the narrow MoSi meander for which no crossover current is observed, thus suggesting different photon detection mechanisms in the wide and narrow strips. Namely, we argue that in the wide strip the absorbed photon destroys superconductivity locally via the vortex-antivortex mechanism for the emergence of resistance while in the narrow meander superconductivity is destroyed across the whole stripline, forming a hot belt. Accordingly, the different photon detection mechanisms associated with vortices and the hot belt stipulate the qualitative difference in the dependence of the photon count rate on the magnetic field.