Where Schrödinger’s cat came from – and why it’s getting fatter

Several weeks ago, I was huddled over a laptop with two researchers from IBM to learn about a Schrödinger’s cat they had made in one of their quantum computers. It was a big one – big enough, I learned, to be considered proof that their computer was worth paying attention to.

Now, this wasn’t a real cat with paws and whiskers, of course, but a metaphorical one made from tiny superconducting circuits called…