Ultracold atoms achieve Laughlin and fractional quantum Hall states.

An international team led by Markus Greiner at Harvard has realized a Laughlin state using ultracold neutral atoms manipulated by lasers. The experiment involves trapping a few atoms in an optical box and implementing the ingredients required for the creation of this exotic state: a strong synthetic magnetic field and strong repulsive interactions among the atoms. The researchers imaged the atoms one by one through a powerful quantum-gas microscope and demonstrated the peculiar "dance" of the particles, which orbit around each other, as well as the fractional nature of the realized atomic Laughlin state. This milestone opens the door to a wide new field of exploration of Laughlin states and their cousins in quantum simulators.