PORTLAND, Ore. -- Room-temperature superconductivity has been a research goal since resistance-less conduction of electricity was discovered in 1911. Unfortunately, researchers have yet to find a theoretical framework for explaining why some materials exhibit superconductivity at higher temperatures than others.
Now, the Energy Department's Oak Ridge National Laboratory claims to have discovered a theoretical explanation for why some materials have been found experimentally to superconduct at higher temperatures than others, opening the door to crafting designer materials that superconduct at room temperature.
"We found that stripe-like inhomogeneities in electron density--where there is less charge--can enhance superconductivity at higher temperatures," said Oak Ridge researcher Thomas Maier.
Experiments found that superconductors often exhibited variations in charge density, prompting researchers to rewrite code for their numerical Hubbard model of superconducting copper compounds (called cuprates) from being homogenous to having various types of inhomogeneities.
The Oak Ridge researchers found that inhomogeneities arranged in parallel stripes, a few atomic layers apart, raised the temperature of superconductivity closer to room temperature, but that completely random inhomogeneities tended to suppress superconductivity.
Next, the researchers want to explore various different types of homogeneity--besides stripes--to see if other patterns may hold the key to achieving room-temperature superconductivity. The researcher is theoretical, for now, and advances will depend on further work elsewhere to try out various topologies for achieving room-temperature superconductivity.