A quarter century ago, the qubit was born
In 1992, a physicist invented a concept that would drive a new type of computing
INDECISIVE INFO A qubit can exist as both a 0 and 1. When the qubit is represented on a sphere, the angles formed by the radius determine the odds of measuring a 0 or 1.
L. Lo
John Archibald Wheeler was fond of clever phrases.
He made the term “black hole” famous in the 1960s. He also coined the now-familiar “wormhole” and “quantum foam.” While further pondering the mystery of quantum physics at the University of Texas at Austin during the 1980s, Wheeler repeatedly uttered his favorite interrogative slogan: “How come the quantum?” And from those ponderings emerged yet another memorable phrase: “It from Bit.” That became a meme that inspired a surprising new field of physics — quantum information theory.
That theory’s basic unit, the qubit, made its scientific debut at a conference in Dallas 25 years ago. Wheeler didn’t invent the term qubit. One of his former students, Benjamin Schumacher, coined it to refer to a bit of quantum information. At the time, few people appreciated the importance of information in quantum physics. And hardly anyone realized how
