In a paper published in the March 7 online edition of Nature Physics, Zhang and his colleagues describe an experimental set-up that could detect for the first time the axion, a theoretical tiny, lightweight particle conjectured to permeate the universe. With its very small mass and lack of electric charge, the axion is a candidate for the mysterious dark matter particle. Yet, despite much effort, the axion has never been observed experimentally.
That may change thanks to the SIMES theorists’ forefront research into topological insulators. In this small, newly discovered subset of materials, electrons travel with great difficulty through the interior but flow with much less resistance on the surface, much as they can in superconductive materials. Even better, they do this at room temperature. This leads to unusual properties that may be important for applications such as spintronics, an emerging technology that could allow for a new class of low-power, high-density, superior-performance electronic devices.
In their research into other applications for topological insulators, Zhang and his colleagues discovered that the electromagnetic behavior of topological insulators is described by the very same mathematical equations that describe the behavior of axions; wondrously, the laws of the universe related to axions are mirrored in this new class of materials. As a result of this mathematical parallel, the theorists posit that experiments on topological insulators can reveal much about the axions that are predicted to pervade the universe.