The signal carriers in these 2D superconductors are not electrons – as with traditional silicon-based technologies – but Dirac or Majorana fermions, particles without mass that move at nearly the speed of light. The researchers claim the materials could become building blocks of future quantum computers and other advanced electronics.
Using a fibre-optic Sagnac interferometer microscope, the team observed magnetism in a microscopic flake of chromium germanium telluride (CGT), which they created. The compound was viewed at -197°C and is said to be a cousin of graphene.
Certain computer components, such as memory and storage systems, need to be made of materials that have both electronic and magnetic properties. Graphene has the former but not the latter. CGT, however, is said to have both.
The Sagnac interferometer was also used to examine what happens at the precise moment bismuth and nickel are brought into contact with one another at -233°C. The team found at the interface between the two metals a superconductor that breaks time-reversal symmetry.
"Imagine you turn back the clock and a cup of red tea turns green. Wouldn't that make this tea very exotic? This is indeed exotic for superconductors," said UCI associate professor Jing Xia. "And it's the first time it's been observed in 2D materials.”
"The issue now is to try to achieve this at normal temperatures," Xia concluded.