Optical trapping of an ion

Isolating ions and atoms from the environment is essential in experiments on a quantum level 1 , 2 , 3 , 4 . For decades, this has been achieved by trapping ions with radiofrequency 5 fields and neutral particles with optical fields 6 . Here we demonstrate the trapping of an ion by interaction with light. The lifetime in the optical trap is several milliseconds, allowing hundreds of oscillations in the optical potential, and could be enhanced by established methods 6 . These results could form the starting point for combining the advantages of optical trapping and ions. Extending the approach to optical lattices could support developments in experimental quantum simulations 7 . As well as simulating complex spin systems with trapped ions, a new class of quantum simulations could be enabled that combines atoms and ions in a common lattice (Cirac, J.I., personal communication; Zoller, P., personal communication). Furthermore, ions could be embedded into quantum degenerate gases, thereby avoiding the inevitable excess kinetic energy of ions in radiofrequency traps, which currently limits cold-chemistry experiments 8 , 9 . It is well-known that neutral atoms can be trapped using visible light, but the trapping of ions is typically achieved using radiofrequency electromagnetic fields. Researchers have now developed an optical ion trapping technique that may be useful for applications ranging from quantum physics to ultracold chemistry.