Scientists at the U.S. National Institute of Standards and Technology, in Boulder, Colo., have developed a superconducting device that acts like a hyperefficient version of a human synapse.
Neural synapses are the connections between neurons, and changes in the strength of those connections are how neural networks learn. The NIST team has come up with a superconducting synapse made with nanometer-scale magnetic components that is so energy efficient, it appears to beat human synapses by a factor of 100 or more.
“The NIST synapse has lower energy needs that the human synapse, and we don’t know of any other artificial synapse that uses less energy,” NIST physicist Mike Schneider said in a press release.
The heart of this new synapse is a device called a magnetic Josephson junction. An ordinary Josphson junction is basically a “weak link between superconductors,” explains Schneider. Up to a certain amperage, current will flow with no voltage needed through such a junction by tunneling across the weak spot, say a thin sliver of non-superconducting material. However, if you push more electrons through until you pass a “critical current,” the voltage will spike at an extremely high rate—100 gigahertz or more.