Reduced Deadtime and Higher Rate Photon-Counting Detection using a Multiplexed Detector Array

Efficient heralding of O-band passively spatial-multiplexed photons for noise-tolerant quantum key distribution

When implementing O-band quantum key distribution on optical fiber transmission lines carrying C-band data traffic, noise photons that arise from spontaneous Raman scattering or insufficient filtering of the classical data channels could cause the quantum bit-error rate to exceed the security threshold. In this case, a photon heralding scheme may be used to reject the uncorrelated noise photons in order to restore the quantum bit-error rate to a low level. However, the secure key rate would suffer unless one uses a heralded photon source with sufficiently high heralding rate and heralding effi…

Limits of the time-multiplexed photon-counting method

The progress in building large quantum states and networks requires sophisticated detection techniques to verify the desired operation. To achieve this aim, a cost- and resource-efficient detection method is the time multiplexing of photonic states. This design is assumed to be efficiently scalable; however, it is restricted by inevitable losses and limited detection efficiencies. Here, we investigate the scalability of time-multiplexed detectors under the effects of fiber dispersion and losses. We use the distinguishability of Fock states up to $n=20$ after passing the time-multiplexed detect…

可观察的非经典性见证者用于多路检测系统

Observable nonclassicality witnesses for multiplexed detection systems

本研究提出了一种基于半整数次点击矩的非经典性见证方法，适用于多路复用光学系统，能够有效探测偶极子和奇极子态。

Uncovering Quantum Correlations with Time-Multiplexed Click Detection

We report on the implementation of a time-multiplexed click detection scheme to probe quantum correlations between different spatial optical modes. We demonstrate that such measurement setups can uncover nonclassical correlations in multimode light fields even if the single mode reductions are purely classical. The nonclassical character of correlated photon pairs, generated by a parametric down-conversion, is immediately measurable employing the theory of click counting instead of low-intensity approximations with photoelectric detection models. The analysis is based on second- and higher-ord…

多路复用光子数分辨探测器的理论框架

Theory Framework of Multiplexed Photon-Number-Resolving Detectors

本研究提出多路复用光子数分辨探测器的理论框架，证明其在光子数矩估计误差与探测器数量成反比，并展示了在猫态生成中的应用优势。

High-speed phonon imaging using frequency-multiplexed kinetic inductance detectors

We present a measurement of phonon propagation in a silicon wafer utilizing an array of frequency-multiplexed superconducting resonators coupled to a single transmission line. The electronic readout permits fully synchronous array sampling with a per-resonator bandwidth of 1.2 MHz, allowing sub-$μ$s array imaging. This technological achievement is potentially vital in a variety of low-temperature applications, including single-photon counting, quantum-computing and dark-matter searches.