Physicists at MIT made the discovery working with graphene, an atom-thin material made from carbon atoms that are linked in a hexagonal pattern.
This ability to switch the superconductivity on and off was particular to graphene when it was stacked in specific way – known as magic-angle graphene.
According to MIT, the discovery could lead to “ultrafast, energy-efficient superconducting transistors for neuromorphic devices — electronics designed to operate in a way similar to the rapid on/off firing of neurons in the human brain.”
As its name suggests, magic-angle graphene has already revealed some surprising properties. In 2018, MIT researchers led by Pablo Jarillo-Herrero were able to demonstrate that the material could behave as an insulator when a certain continuous electric field was applied.
Surprisingly, when they the field was increased, the material morphed into a superconductor, allowing electrons to flow, friction-free.
These discoveries were part of the emerging field of ‘twistronics,’ which explores how twisting and layering materials can give rise to new electronic properties.
The revelation that the graphene’s superconductivity could be turned on and off so rapidly came about through a combination of twisting and stacking of the material, Jarillo-Herrero and his team found out.
“For the vast majority of materials, if you remove the electric field, zzzzip, the electric state is gone,” says Jarillo-Herrero, who is the Cecil and Ida Green Professor of Physics at MIT. “This is the first time that a superconducting material has been made that can be electrically switched on and off, abruptly. This could pave the way for a new generation of twisted, graphene-based superconducting electronics.”
A paper on the new findings has been published in Nature Nanotechnology.