Scientists at Cambridge University are working on combining two fields of solid state physics research, spintronics and superconductors, in order to develop what they hope could become the foundation for the next generation of datacenter technology — perhaps within the next decade.
Data centers are the engines of the digital economy. But they are also very energy intensive in their own right — with the researchers citing estimates that some three per cent of the power generated in Europe is already being used by data centers.
One impetus for the research is therefore to apply ‘superspin’ technology to substantially reduce the power consumption of high performance computing and data storage. Superconductors allow for the propagation of electrical charge without electronic resistance, and therefore hold out the tantalizing promise — in computing kit terms — of carrying electronic charge with zero energy loss.
Albeit, at this stage in the research, there is still a question mark over whether the cooling requirements of utilizing superconductors will result in less energy consumption overall or not. Hence the need for further research.
“Superconductivity necessarily requires low temperature,” explains Dr Jason Robinson, one of the project leads. “No one has discovered room temperature superconductivity.
“The crunch question is: is the energy required to cool going to be smaller than current energy loss due to the energy efficiency of spintronics. If it costs more to cool than it currently does in terms of what we lose, currently, then it’s not worth it. That’s what we’re exploring.”
“Our basic calculations suggest that superconducting spintronics will be massively more energy efficient than current spintronics,” he adds.
Another driver for the research is to use superspin as a possible alternative to semiconductor technology — as a new route to sustain Moore’s Law of shrinking electronics, just as the ability of engineers to pack more transistors onto integrated circuits is starting to look like it’s coming to the end of the road. Spintronics proposes utilizing the spin alignment of electrons as a medium to store (the 0 or 1 of) digital data.
“Information technology now is based on such small objects you just can’t use conventional superconductors,” notes Robinson. “By combining superconductivity with spintronics it’s not only that you can create circuits without [energy] dissipation, but it’s that you create new physics. So that means there’s a lot of new opportunities created through this combination.
“There’s a lot of undiscovered physics to be explored.”
The Cambridge-led project has received a £2.7 million grant from the UK’s Engineering and Physical Sciences Research Council, with a focus on developing a superconducting spintronics prototype device over the next five years to prove out their theoretical modeling that the combined tech is indeed more energy efficient than just using spintronics.
“It’s important to understand that this is the first ever superconductivity and spintronics funded program,” adds Robinson. “The way the grant has been set up in the first three years there’s a series of parallel projects. Some are more applications biased than others but the application stuff has to develop alongside the science… Everything we do is moving us towards the prototype.”
“It’s a fundamental program with the aim of triggering applications in spintronics. There’s a lot of science we don’t currently understand and we need to understand in order to be able to make the best possible prototype. We have enough science to know that we can make a prototype. The question is can we make the best prototype,” he adds. “[And] what do we need to do in order to be able to make a device that’s switchable — that you can not only store information on, but you can process information with as well.”
The project draws on prior research conducted at Cambridge, and elsewhere, to combine spintronics and superconductors — a feat previously thought to be impossible, thanks to superconductivity canceling out electronic spin.
However the same research group at Cambridge found a workaround for that, involving magnets. Initially utilizing a layer of a rare earth magnetic material — although the group has since proved that various magnetic materials can be used, according to Robinson.
“A few years ago our group discovered that actually if you combine supercomputers with magnets you can create a new kind of Cooper Pair [paired electrons], which instead of having two electrons with anti-parallel spins you can create pairs which have parallel line spins. So now you have both the benefits of superconductivity and the ability to carry spin in the superconducting state.”
Another area he is excited about from the combination of superconductivity and spintronics is the potential for using the technique to further quantum computing.
“It introduces lots of new ideas that were not possible previously. So that’s exciting, and indeed a large part of our grant is to develop the science of those other areas as well,” he adds.