While modern computers still operate on classical electricity, they are quickly approaching the quantum level as sizes shrink. This is a problem many recognize because quantum mechanics may lead to unpredictable swings in conductance within a processor. Now researchers at McGill University and General Motors R&D have found the problem could be even worse.
Silicon is definitely the best known material within our computers, but it is hardly the only one. Metals such as gold and tungsten are used as well, such as to connect components of a device. It turns out that at the quantum level, that connect is not very good. Even with a perfect interface between the two metals, the electrical current through them would be a quarter of what is applied. The experimental results bore this out by being an order of magnitude less or one tenth the applied current, thanks to the imperfections of reality.
While the current drop may be quite bad, at least now we know it exists, and to what degree. The next steps are to find a solution or find other metals to do the job without increasing resistance.