Atomic and molecular physics

  • Article |

    Laser-free universal control of two trapped-ion qubits using a combination of radiofrequency and microwave magnetic fields achieves some of the highest fidelities ever reported for two-qubit maximally entangled states.

    • R. Srinivas
    • , S. C. Burd
    •  & D. H. Slichter
  • Article |

    Directly coupling cavity photons to the photo-association resonances of pairs of atoms in a strongly interacting Fermi gas generates pair polaritons—hybrid excitaions coherently mixing photons, atom pairs and molecules.

    • Hideki Konishi
    • , Kevin Roux
    •  & Jean-Philippe Brantut
  • Article
    | Open Access

    A single electromagnetically trapped proton is sympathetically cooled to below ambient temperature by coupling it through a superconducting LC circuit to a laser-cooled cloud of Be+ ions stored in a spatially separated trap.

    • M. Bohman
    • , V. Grunhofer
    •  & S. Ulmer
  • Article
    | Open Access

    A globally chiral atomic superfluid is induced by time-reversal symmetry breaking in an optical lattice and exhibits global angular momentum, which is expected to lead to topological excitations and the demonstration of a topological superfluid.

    • Xiao-Qiong Wang
    • , Guang-Quan Luo
    •  & Zhi-Fang Xu
  • Article |

    A programmable quantum simulator with 256 qubits is created using neutral atoms in two-dimensional optical tweezer arrays, demonstrating a quantum phase transition and revealing new quantum phases of matter.

    • Sepehr Ebadi
    • , Tout T. Wang
    •  & Mikhail D. Lukin
  • Article |

    Operating in space, NASA’s Deep Space Atomic Clock, a trapped-ion clock, is shown to have long-term stability and drift that are an order of magnitude better than current space clocks.

    • E. A. Burt
    • , J. D. Prestage
    •  & T. A. Ely
  • Article |

    First and second sound are experimentally observed in a two-dimensional superfluid, and the temperature-dependent sound speeds reveal the predicted jump in the superfluid density at the infinite-order Berezinskii–Kosterlitz–Thouless transition.

    • Panagiotis Christodoulou
    • , Maciej Gałka
    •  & Zoran Hadzibabic
  • Article |

    A Bose-Einstein condensate of molecules is produced by pairing atoms in an atomic condensate; this transition is the bosonic analog of the Bardeen-Cooper-Schrieffer superfluid to BEC crossover in Fermi gases.

    • Zhendong Zhang
    • , Liangchao Chen
    •  & Cheng Chin
  • Article |

    The quantum charge-coupled device architecture is demonstrated, with its various elements integrated into a programmable trapped-ion quantum computer and performing simple quantum operations with state-of-the-art levels of error.

    • J. M. Pino
    • , J. M. Dreiling
    •  & B. Neyenhuis
  • Article
    | Open Access

    The successful laser cooling of trapped antihydrogen, the antimatter atom formed by an antiproton and a positron (anti-electron), is reported.

    • C. J. Baker
    • , W. Bertsche
    •  & J. S. Wurtele
  • Article
    | Open Access

    The 2S–2P transitions in muonic helium-4 ions are measured using laser spectroscopy and used to obtain an α-particle charge-radius value five times more precise than that from electron scattering.

    • Julian J. Krauth
    • , Karsten Schuhmann
    •  & Franz Kottmann
  • Article |

    A many-atom state of trapped 171Yb atoms that are entangled on an optical atomic-clock transition overcomes the standard quantum limit, providing a proof-of-principle demonstration towards entanglement-based optical atomic clocks.

    • Edwin Pedrozo-Peñafiel
    • , Simone Colombo
    •  & Vladan Vuletić
  • Article |

    Spin transport far from equilibrium is studied in a Heisenberg model with adjustable anisotropy realized with coupled ultracold 7Li atoms, and different dynamical regimes are found for positive and negative anisotropies.

    • Paul Niklas Jepsen
    • , Jesse Amato-Grill
    •  & Wolfgang Ketterle
  • Article |

    A strongly interacting gas of polar molecules is created by combining an electric field with two-dimensional optical confinement, enabling evaporative cooling and opening up the exploration of low-entropy many-body phases.

    • Giacomo Valtolina
    • , Kyle Matsuda
    •  & Jun Ye
  • Article |

    An atomic simulator formed of a few ultracold fermionic atoms trapped in a two-dimensional harmonic potential exhibits precursors of a quantum phase transition, revealing the onset of collective quantum many-body phenomena in a few-body system.

    • Luca Bayha
    • , Marvin Holten
    •  & Selim Jochim
  • Article
    | Open Access

    Measurements of low-energy electronic states of radium monofluoride validate predictions of the use of this short-lived radioactive molecule in exploring fundamental physics and provide evidence of its suitability for laser cooling.

    • R. F. Garcia Ruiz
    • , R. Berger
    •  & X. F. Yang
  • Article |

    Quantum entanglement is realized between rotational levels of a molecular ion with energy differences spanning several orders of magnitude and long-lived internal states of a single atomic ion.

    • Yiheng Lin
    • , David R. Leibrandt
    •  & Chin-wen Chou
  • Article |

    Long-lived pionic helium atoms (composed of a helium-4 nucleus, an electron and a negatively charged pion) are synthesized in a superfluid-helium target, as confirmed by laser spectroscopy involving the pion-occupied orbitals.

    • Masaki Hori
    • , Hossein Aghai-Khozani
    •  & Daniel Barna
  • Article |

    NaLi molecules are cooled to micro- and nanokelvin temperatures through collisions with ultracold Na atoms by using molecules and atoms in stretched hyperfine spin states and applying two evaporation stages.

    • Hyungmok Son
    • , Juliana J. Park
    •  & Alan O. Jamison
  • Article |

    Precision measurements of the 1S–2P transition in antihydrogen that take into account the standard Zeeman and hyperfine effects confirm the predictions of quantum electrodynamics.

    • M. Ahmadi
    • , B. X. R. Alves
    •  & J. S. Wurtele
  • Article |

    The precision of laser spectroscopy of highly charged ions is improved by eight orders of magnitude by cooling trapped, highly charged ions and using quantum logic spectroscopy, thereby enabling tests of fundamental physics.

    • P. Micke
    • , T. Leopold
    •  & P. O. Schmidt
  • Article |

    A driven–dissipative gas of ultracold potassium atoms is used to demonstrate three key signatures of self-organized criticality, and provides a system in which the phenomenon can be experimentally tested.

    • S. Helmrich
    • , A. Arias
    •  & S. Whitlock
  • Letter |

    An analogue quantum simulator based on ultracold atoms in optical lattices and cavity quantum electrodynamics is proposed for the solution of quantum chemistry problems and tested numerically for a simple molecule.

    • Javier Argüello-Luengo
    • , Alejandro González-Tudela
    •  & J. Ignacio Cirac
  • Letter |

    Observation of the collective mode responding to the superfluid stiffness—the low-energy Goldstone mode—provides direct evidence for phase rigidity, which is a key signature of supersolidity in an ultracold quantum gas.

    • Mingyang Guo
    • , Fabian Böttcher
    •  & Tilman Pfau
  • Letter |

    Quantum critical behaviour at the many-body localization transition in a disordered Bose–Hubbard system of bosonic rubidium atoms in an optical lattice is observed, connecting the macroscopic phenomenology of the transition to the system’s microscopic quantum correlations.

    • Matthew Rispoli
    • , Alexander Lukin
    •  & Markus Greiner
  • Letter |

    Magnetic polarons are imaged with single-site spin and density resolution in the low-doping regime of the atomic Fermi–Hubbard model, showing that mobile delocalized doublons are necessary for polaron formation.

    • Joannis Koepsell
    • , Jayadev Vijayan
    •  & Christian Gross
  • Letter |

    Multi-qubit entangling gates are realized by simultaneously driving multiple motional modes of a linear chain of trapped ions with modulated external fields, achieving a fidelity of about 93 per cent with four qubits.

    • Yao Lu
    • , Shuaining Zhang
    •  & Kihwan Kim
  • Letter |

    Number-state superpositions of the harmonic motion of a trapped beryllium ion are used to measure the oscillation frequency with quantum-enhanced sensitivity, achieving a mode-frequency uncertainty of about 10−6.

    • Katherine C. McCormick
    • , Jonas Keller
    •  & Dietrich Leibfried
  • Letter |

    Frequency modulation is used to create ‘Floquet polaritons’—strongly interacting quasi-particles that exist in a customizable set of modes.

    • Logan W. Clark
    • , Ningyuan Jia
    •  & Jonathan Simon