Superconducting optoelectronic hardware is being explored as a path towards
artificial spiking neural networks with unprecedented scales of complexity and
computational ability. Such hardware combines integrated-photonic components
for few-photon, light-speed communication with superconducting circuits for
fast, energy-efficient computation. Monolithic integration of superconducting
and photonic devices is necessary for the scaling of this technology. In the
present work, superconducting-nanowire single-photon detectors are
monolithically integrated with Josephson junctions for the first time, enabling
the realization of superconducting optoelectronic synapses. We present circuits
that perform analog weighting and temporal leaky integration of single-photon
presynaptic signals. Synaptic weighting is implemented in the electronic domain
so that binary, single-photon communication can be maintained. Records of
recent synaptic activity are locally stored as current in superconducting
loops. Dendritic and neuronal nonlinearities are implemented with a second
stage of Josephson circuitry. The hardware presents great design flexibility,
with demonstrated synaptic time constants spanning four orders of magnitude
(hundreds of nanoseconds to milliseconds). The synapses are responsive to
presynaptic spike rates exceeding 10 MHz and consume approximately 33 aJ of
dynamic power per synapse event before accounting for cooling. In addition to
neuromorphic hardware, these circuits introduce new avenues towards realizing
large-scale single-photon-detector arrays for diverse imaging, sensing, and
quantum communication applications.

该论文探讨了超导光电硬件作为通往具有前所未有的复杂性和计算能力的人工脉冲神经网络的一种方法，并研究了单光子探测器与约瑟夫森结的单片集成，以实现超导光电突触，并介绍了执行单光子突触前突触信号的模拟加权和时间泄漏积分的电路，响应前突触脉冲速率达 10 MHz，耗电量约为 33 aJ。

超导光电单光子突触的演示

Demonstration of Superconducting Optoelectronic Single-Photon Synapses

Gaussian boson sampling exploits squeezed states to provide a highly
efficient way to demonstrate quantum computational advantage. We perform
experiments with 50 input single-mode squeezed states with high
indistinguishability and squeezing parameters, which are fed into a 100-mode
ultralow-loss interferometer with full connectivity and random transformation,
and sampled using 100 high-efficiency single-photon detectors. The whole
optical set-up is phase-locked to maintain a high coherence between the
superposition of all photon number states. We observe up to 76 output
photon-clicks, which yield an output state space dimension of $10^{30}$ and a
sampling rate that is $10^{14}$ faster than using the state-of-the-art
simulation strategy and supercomputers. The obtained samples are validated
against various hypotheses including using thermal states, distinguishable
photons, and uniform distribution.

使用高度相似和压缩参数的 50 个输入单模压缩态，通过 100 模超低损耗干涉仪进行随机变换和采样，以及 100 个高效单光子探测器进行采样，实现了一个 $10^{30}$ 维的输出状态空间，采样速率比使用先进模拟策略和超级计算机快了 $10^{14}$，并通过多种假设进行了验证。

使用光子实现量子计算优势

Quantum computational advantage using photons

Single-photon detectors (SPDs) at near infrared wavelengths with high system
detection efficiency (> 90%), low dark count rate (< 1 counts per second, cps),
low timing jitter (< 100 ps), and short reset time (< 100 ns) would enable
landmark experiments in a variety of fields. Although some of the existing
approaches to single-photon detection fulfill one or two of the above
specifications, to date no detector has met all of the specifications
simultaneously. Here we report on a fiber-coupled single-photon-detection
system employing superconducting nanowire single photon detectors (SNSPDs) that
closely approaches the ideal performance of SPDs. Our detector system has a
system detection efficiency (SDE), including optical coupling losses, greater
than 90% in the wavelength range \lambda = 1520-1610 nm; device dark count rate
(measured with the device shielded from room-temperature blackbody radiation)
of ~ 0.01 cps; timing jitter of ~ 150 ps FWHM; and reset time of 40 ns.

本论文报道了一种光纤耦合单光子检测系统，采用超导纳米线单光子探测器，接近于理想性能。该检测系统在波长范围为 1520-1610 nm 的系统探测效率，包括光耦合损耗，大于 90％，设备暗计数率约为 0.01 cps，时间抖动约为 150 ps FWHM，并且重置时间为 40 ns。