An international team led by University of Toronto physicists has developed a simple new technique to induce high-temperature superconductivity in a semiconductor for the first time – using Scotch Tape.
The method paves the way for new devices that could be used in quantum computing and to improve energy efficiency.
“Who would have thought simply sticking things together can generate entirely new effects?” said team leader and U of T physicist Ken Burch.
High-temperature superconductors are materials that conduct electricity without heating up or losing energy at liquid nitrogen temperatures. Used to transmit electricity with low loss, these superconductors are also the building blocks of the next generation of devices such as quantum computers.
However, only certain compounds of iron, copper and oxygen – or cuprates – reveal high-temperature superconducting properties. Cuprates were believed to be impossible to incorporate with semi-conductors, so their use has been severely limited as has the exploration of new effects they may generate.
For example, observing the phenomenon of the proximity effect – wherein the superconductivity in one material generates superconductivity in an otherwise normal semi-conductor – has been difficult because the fundamental quantum mechanics require the materials to be in nearly perfect contact.
That’s where the tape comes in – specifically, Scotch poster tape: a thin, two-sided version of Scotch Tape.
“Typically, junctions between semi-conductors and superconductors were made by complex material growth procedures and fabricating devices with features smaller than a human hair,” explains Burch. “However the cuprates have a completely different structure and complex chemical make-up that simply can’t be incorporated with a normal semiconductor.”