Measuring chaos: Researchers quantify the quantum butterfly effect

For the first time, researchers in China have accurately quantified how chaos increases in a quantum many-body system as it evolves over time. Combining experiments and theory, a team led by Yu-Chen Li at the University of Science and Technology of China showed that the level of chaos grows exponentially when time reversal is applied to these systems—matching predictions of their extreme sensitivity to errors. The research has been published in Physical Review Letters.