Quantum state teleportation verifies information scrambling

A quantum circuit that can unambiguously test for information scrambling in an experiment could help verify the calculations of quantum computers and even shed more light on what happens to quantum information when it falls into a black hole. The new test, designed by researchers at the Joint Quantum Institute at the University of Maryland in the US, involves carefully manipulating the quantum behaviour of seven charged ions using well-timed sequences of laser pulses. It correctly determines whether information has been scrambled (as opposed to being completely lost) to an accuracy of around 80%.