MIT researchers may have found a way to overcome a key barrier to the advent of super-fast quantum computers, which could be powerful tools for applications such as code breaking. Ever since Nobel Prize-winning physicist Richard Feynman first proposed the theory of quantum computing more than two decades ago, researchers have been working to build such a device. One approach involves superconducting devices that, when cooled to temperatures of nearly absolute zero (-459 deg F, -273 deg C).