Electrical Characteristics of Superconducting Nanowire Single Photon Detector

IEEE J. Select. Topics Quantum Electron.

2020

Much of the information processing performed by a neuron occurs in the dendritic tree. For neural systems using light for communication, it is advantageous to convert signals to the electronic domain at synaptic terminals so dendritic computation can be performed with electrical circuits. Here we present circuits based on Josephson junctions and mutual inductors that act as dendrites, processing signals from synapses receiving single-photon communication events with superconducting detectors. We show simulations of circuits performing basic temporal filtering, logical operations, and nonlinear transfer functions. We further show how the synaptic signal from a single-photon can fan out locally in the electronic domain to enable the dendrites of the receiving neuron to process a photonic synapse event or pulse train in multiple different ways simultaneously. Such a technique makes efficient use of photons, energy, space, and information.

Section: Photon-to-fluxon Transduction At a Synapsementioning

confidence: 99%

Fluxonic Processing of Photonic Synapse Events

IEEE J. Select. Topics Quantum Electron.

2020

“…We design a device that performs the operation of transducing single-photon signals to supercurrent stored in a loop. The circuit utilizes superconducting-nanowire single-photon detectors (SPDs) [25][26][27][28] in conjunction with Josephson junctions (JJs) [29][30][31] and mutual inductors [32] to achieve the desired operations. Modification of a current bias can change the synaptic weight of the connection, and we present designs for receiver circuits in neurons with 10, 100, and 1000 synaptic connections.…”

Section: Introductionmentioning

confidence: 99%

Superconducting optoelectronic loop neurons

Journal of Applied Physics

Buckley

McCaughan

et al. 2019

Circuits using superconducting single-photon detectors and Josephson junctions to perform signal reception, synaptic weighting, and integration are investigated. The circuits convert photondetection events into flux quanta, the number of which is determined by the synaptic weight. The current from many synaptic connections is inductively coupled to a superconducting loop that implements the neuronal threshold operation. Designs are presented for synapses and neurons that perform integration as well as detect coincidence events for temporal coding. Both excitatory and inhibitory connections are demonstrated. It is shown that a neuron with a single integration loop can receive input from 1000 such synaptic connections, and neurons of similar design could employ many loops for dendritic processing.

“…Superconducting single-photon detectors [58], [59], [60], [57] will perform well receiving communication events between neurons. The use of superconductors in large-scale cognitive systems contributes to energy efficiency by enabling single-photon communication and also because the superconducting circuits draw near zero power when not responding to a detection event.…”

Section: Power: As Few Photons As Possiblementioning

confidence: 99%

The Largest Cognitive Systems Will be Optoelectronic

2018 IEEE International Conference on Rebooting Computing (ICRC)

2018

Electrons and photons offer complimentary strengths for information processing. Photons are excellent for communication, while electrons are superior for computation and memory. Cognition requires distributed computation to be communicated across the system for information integration. We present reasoning from neuroscience, network theory, and device physics supporting the conjecture that large-scale cognitive systems will benefit from electronic devices performing synaptic, dendritic, and neuronal information processing operating in conjunction with photonic communication. On the chip scale, integrated dielectric waveguides enable fan-out to thousands of connections. On the system scale, fiber and free-space optics can be employed. The largest cognitive systems will be limited by the distance light can travel during the period of a network oscillation. We calculate that optoelectronic networks the area of a large data center (10 5 m 2 ) will be capable of system-wide information integration at 1 MHz. At frequencies of cortex-wide integration in the human brain (4 Hz, theta band), optoelectronic systems could integrate information across the surface of the earth.