Fast Spiking of a Mott VO2-Carbon Nanotube Composite Device

TL;DR

This paper demonstrates a VO2-carbon nanotube device capable of rapid, energy-efficient spiking with sub-20 ns pulses, advancing neuromorphic computing and nanoscale device power-scaling.

Contribution

It introduces a novel VO2-CNT composite device that significantly enhances spiking speed and energy efficiency compared to VO2-only devices.

Findings

Achieved sub-20 ns pulse width spiking.

Added nanotube heater reduces transient duration and pulse energy.

Increased spiking frequency by up to three orders of magnitude.

Abstract

The recent surge of interest in brain-inspired computing and power-efficient electronics has dramatically bolstered development of computation and communication using neuron-like spiking signals. Devices that can produce rapid and energy-efficient spiking could significantly advance these applications. Here we demonstrate DC-current or voltage-driven periodic spiking with sub-20 ns pulse widths from a single device composed of a thin VO2 film with a metallic carbon nanotube as a nanoscale heater. Compared with VO2-only devices, adding the nanotube heater dramatically decreases the transient duration and pulse energy, and increases the spiking frequency, by up to three orders of magnitude. This is caused by heating and cooling of the VO2 across its insulator-metal transition being localized to a nanoscale conduction channel in an otherwise bulk medium. This result provides an important component of energy-efficient neuromorphic computing systems, and a lithography-free technique for power-scaling of electronic devices that operate via bulk mechanisms.