Single-photon detectors are ubiquitous devices in quantum-photonic-based communication, computation, metrology, and sensing. In these applications, N-fold coincidence photon counting is often needed, for example, to characterize entanglement. However, N-fold coincidence photon counting typically requires N individual single-photon detectors and associated bias and readout electronics, and these resources could become prohibitive if N goes large and the detectors need to work at cryogenic temperatures. Here, to break this limit on N, we propose a device architecture based on N cascaded photosensitive superconducting nanowires and one wider nanowire that functions as a current reservoir. We show that by strategically designing the device, the network of these superconducting nanowires can work in a synergic manner as an n-photon detector, where n can be from 1 to N, depending on the bias conditions. We therefore name the devices of this type superconducting nanowire multi-photon detectors (SNMPDs). In addition to its simple one-port bias and readout circuitry, the coincidences are counted internally in the detector, eliminating the need for external multi-channel, time-correlated pulse counters. We believe that the SNMPDs proposed in this work could open avenues towards conveniently measuring high-order temporal correlations of light and characterizing multi-photon entanglement.

中文翻译：

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由电流储存器启用的超导纳米线多光子探测器

单光子探测器是基于量子光子的通信、计算、计量和传感中无处不在的设备。在这些应用中，通常需要 N 重重合光子计数，例如，表征纠缠。然而，N 重符合光子计数通常需要 N 个单独的单光子探测器以及相关的偏置和读出电子设备，如果 N 变大并且探测器需要在低温下工作，这些资源可能会变得令人望而却步。在这里，为了打破对 N 的这一限制，我们提出了一种基于 N 级联光敏超导纳米线和一根更宽的纳米线作为电流储存器的器件架构。我们表明，通过战略性地设计设备，这些超导纳米线的网络可以作为 n 光子探测器以协同方式工作，其中 n 可以从 1 到 N，具体取决于偏置条件。因此，我们将这种类型的设备命名为超导纳米线多光子探测器 (SNMPD)。除了简单的单端口偏置和读出电路外，重合在检测器内部进行计数，无需外部多通道时间相关脉冲计数器。我们相信，这项工作中提出的 SNMPD 可以为方便地测量光的高阶时间相关性和表征多光子纠缠开辟道路。无需外部多通道时间相关脉冲计数器。我们相信，这项工作中提出的 SNMPD 可以为方便地测量光的高阶时间相关性和表征多光子纠缠开辟道路。无需外部多通道时间相关脉冲计数器。我们相信，这项工作中提出的 SNMPD 可以为方便地测量光的高阶时间相关性和表征多光子纠缠开辟道路。