Physicists See a Quantum Leap, Halt It, and Reverse It

June 11, 2019

Many of the pioneers of quantum mechanics assumed they were instantaneous. A new experiment shows that they aren’t. By making a kind of high-speed movie of a quantum leap, the work reveals that the process is as gradual as the melting of a snowman in the sun. “If we can measure a quantum jump fast and efficiently enough,” said Michel Devoret of Yale University, “it is actually a continuous process.”