The foundations of quantum mechanics were laid down 100 years ago. But many of its strange implications have taken decades to unravel. One is the phenomenon of quantum tunnelling the ability of particles to pass straight through a barrier that shouldn’t be possible according to classical physics, given its energy.Both tunnelling and superposition were known at the atomic scale but hadn’t been observed in macroscopic systems. In the late 1970s, Anthony Leggett, who won the 2003 Nobel Prize in Physics for his theoretical work on superconductors, suggested that the phenomena should be observable at the macroscopic scale using superconducting circuits loops of wire which, when chilled to a fraction of a degree above absolute zero, can conduct electricity without resistance. Is Quantum computing going to revolutionalize the computing industry ?

