Deeper understanding of quantum chaos may be the key to quantum computers

New research gives insight into a recent experiment that was able to manipulate an unprecedented number of atoms through a quantum simulator. This new theory could provide another step on the path to creating the elusive quantum computers.

An international team of researchers, led by the University of Leeds and in cooperation with the Institute of Science and Technology Austria and the University of Geneva, has provided a theoretical explanation for the particularbehaviour of individual atoms that were trapped and manipulated in a recent experiment by Harvard University and MIT. The experiment used a system of finely tuned lasers to act as "optical tweezers" to assemble a remarkably long chain of 51 atoms.

When the quantum dynamics of the atom chain were measured, there were surprising oscillations that persisted for much longer than expected and which couldn't be explained.

Study co-author, Dr. Zlatko Papic, Lecturer in Theoretical Physics at Leeds, said: "The previous Harvard-MIT experiment created surprisingly robust oscillations that kept the atoms in a quantum state for an extended time. We found these oscillations to be rather puzzling because they suggested that atoms were somehow able to "remember" their initial configuration while still moving chaotically.

"Our goal was to understand more generally where such oscillations couldcomefrom, since oscillations signify some kind of coherence in a chaotic environment—and this is precisely what we want from a robust quantum computer. Our work suggests that these oscillations are due to a new physical phenomenon that we called 'quantum many-body scar'."