Oxford physicists froze a quantum particle in place using nothing but the ghost of a magnetic field

In 1959, two physicists predicted something strange: a particle could feel a magnetic field it never touches, simply by traveling around it. Now, Sebastian Saner and colleagues at the University of Oxford have watched that effect — the Aharonov–Bohm effect — play out inside a quantum simulation built from trapped ions, where the magnetic flux froze a tunneling particle in its tracks. Published in Nature Physics, the experiment shows hybrid quantum computers can model fundamental physics that overwhelms ordinary computers.