An odd material, having puzzled physicists for 45 years, has turned out to be an exotic state of matter that could open a new path to quantum computers and other next-generation electronics.
Physicists at the University of Michigan, US, have discovered several properties of the compound samarium hexaboride that has raised hopes for finding the silicon of the quantum era.
The results also close the case of how to classify the material -- a mystery that has been investigated since the late 1960s.
The researchers provide the first direct evidence that samarium hexaboride, abbreviated SmB6, is a topological insulator.
Topological insulators are an exciting class of solids that conduct electricity like a metal across their surface but block the flow of current like rubber through their interior.
The scientists used a novel technique, called torque magnetometry, to observe tell-tale oscillations in the material's response to a magnetic field that reveal how electric current moves through it.
The technique also showed that the surface of samarium hexaboride holds rare Dirac electrons - particles with the potential to help researchers overcome one of the biggest hurdles in quantum computing.
"Before this, no one had found Dirac electrons in a strongly correlated material. We thought strong correlation would hurt them, but now we know it does not," said Lu Li, assistant professor of physics at University of Michigan.
The deeper understanding of samarium hexaboride raises the possibility that engineers might one day route the flow of electric current in quantum computers like they do on silicon in conventional electronics, Li added.
The article appeared in the journal Science.
