It may now be possible to overcome this hurdle, he said, with a phenomenon he has named the spin-voltaic effect, a spin analog of the photovoltaic effect used in solar cells to convert light into electric energy.
"In the spin-voltaic effect, an injected spin produces an electrical signal due to its proximity with a magnetic region," he said, "a signal that could be measurable even in an indirect band gap material like silicon. Reversing the direction of injected spin could lead to switching the direction of electrical current, which can flow even if no electrical voltage has been applied.
"The spin-voltaic effect also can play an important role in providing dynamically tunable current amplification in a novel class of spin transistors, a building block for future spin-logic applications," he said.
Recent work by Zutic's collaborators at the Tokyo Institute of Technology has demonstrated for the first time the spin-voltaic effect in direct band-gap semiconductors.