Researchers have shown that certain superconductors -- materials that carry electrical current with zero resistance at very low temperatures -- can also carry currents of 'spin'. The successful combination of superconductivity and spin could lead to a revolution in high-performance computing, by dramatically reducing energy consumption.
Spin is a particle's intrinsic angular momentum, and is normally carried in non-superconducting, non-magnetic materials by individual electrons. Spin can be 'up' or 'down', and for any given material, there is a maximum length that spin can be carried. In a conventional superconductor electrons with opposite spins are paired together so that a flow of electrons carries zero spin.
A few years ago, researchers from the University of Cambridge showed that it was possible to create electron pairs in which the spins are aligned: up-up or down-down. The spin current can be carried by up-up and down-down pairs moving in opposite directions with a net charge current of zero. The ability to create such a pure spin supercurrent is an important step towards the team's vision of creating a superconducting computing technology which could use massively less energy than the present silicon-based electronics.
Now, the same researchers have found a set of materials which encourage the pairing of spin-aligned electrons, so that a spin current flows more effectively in the superconducting state than in the non-superconducting (normal) state. Their results are reported in the journal Nature Materials.
To read more, click here