Above: IBM's carbon nanotubes have tiny circuits that are fractions of a meter apart.Image Credit: IBM Carbon nanotubes are the leading candidate to replace silicon in semiconductor chips after the decades-long run of silicon electronics runs out. And IBM is hoping to usher along that transition with a new breakthrough being announced today.In the October 2 issue of the journal Science, IBM researchers say they have overcome one of the most daunting challenges around carbon nanotube transistors, which are the building blocks of electronic circuits with dimensions that are measured in billionths of a meter. Carbon nanotubes may be...