Quantum physics

  • Article
    | Open Access

    Existing techniques for high-resolution imaging of trapped quantum gases are limited to two-dimensional systems, but the approach described here works in three dimensions by magnifying the quantum gas with matter wave optics.

    • Luca Asteria
    • , Henrik P. Zahn
    •  & Christof Weitenberg
  • Article |

    An optical lattice for trapping a Bose–Einstein condensate reported here includes photon-mediated atom–atom interactions that replicate acoustic modes in real crystals.

    • Yudan Guo
    • , Ronen M. Kroeze
    •  & Benjamin L. Lev
  • Article |

    A zero-knowledge proof, which can be used to verify secret information, is reported here with security that is enforced by the laws of special relativity.

    • Pouriya Alikhani
    • , Nicolas Brunner
    •  & Hugo Zbinden
  • Article |

    Fault-tolerant circuits for the control of a logical qubit encoded in 13 trapped ion qubits through a Bacon–Shor quantum error correction code are demonstrated.

    • Laird Egan
    • , Dripto M. Debroy
    •  & Christopher Monroe
  • Article |

    Nonlinearity induced by a single photon is desirable because it can drive power consumption of optical devices to their fundamental quantum limit, and is demonstrated here at room temperature.

    • Anton V. Zasedatelev
    • , Anton V. Baranikov
    •  & Pavlos G. Lagoudakis
  • Article |

    Gold nanoflake pairs form by self-assembly in an aqueous ligand solution and offer stable and tunable microcavities by virtue of equilibrium between attractive Casimir forces and repulsive electrostatic forces.

    • Battulga Munkhbat
    • , Adriana Canales
    •  & Timur O. Shegai
  • 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
    | 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 |

    Nonlinearity is shown to induce quantized topological transport via soliton motion; specifically, we demonstrate nonlinear Thouless pumping of photons in waveguide arrays with a non-uniformly occupied energy band.

    • Marius Jürgensen
    • , Sebabrata Mukherjee
    •  & Mikael C. Rechtsman
  • 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 |

    As a blueprint for high-precision quantum simulation, an 18-qubit algorithm that consists of more than 1,400 two-qubit gates is demonstrated, and reconstructs the energy eigenvalues of the simulated one-dimensional wire to a precision of 1 per cent.

    • C. Neill
    • , T. McCourt
    •  & V. Smelyanskiy
  • 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

    A nondestructive detector of photonic qubits, comprising a single 87Rb atom trapped in the centre point of two crossed fibre-based optical resonators, is demonstrated.

    • Dominik Niemietz
    • , Pau Farrera
    •  & Gerhard Rempe
  • Article |

    Using germanium quantum dots, a four-qubit processor capable of single-, two-, three-, and four-qubit gates, demonstrated by the creation of four-qubit Greenberger−Horne−Zeilinger states, is the largest yet realized with solid-state electron spins.

    • Nico W. Hendrickx
    • , William I. L. Lawrie
    •  & Menno Veldhorst
  • Article |

    A reinforcement learning experiment using a programmable integrated nanophotonic processor shows that a quantum communication channel with the environment speeds up the learning process of an agent.

    • V. Saggio
    • , B. E. Asenbeck
    •  & P. Walther
  • Article |

    High-fidelity deterministic quantum state transfer and multi-qubit entanglement are demonstrated in a quantum network comprising two superconducting quantum nodes one metre apart, with each node including three interconnected qubits.

    • Youpeng Zhong
    • , Hung-Shen Chang
    •  & Andrew N. Cleland
  • Article
    | Open Access

    Suitably shaped X-ray pulses are used to coherently steer the quantum dynamics of atoms’ nuclei rather than their electrons, with few-zeptosecond temporal stability of the phase control.

    • Kilian P. Heeg
    • , Andreas Kaldun
    •  & Jörg Evers
  • Article |

    A quantum enhanced search for dark matter that uses vacuum squeezing to overcome the quantum noise limit finds no evidence of dark matter axions in a well motivated mass range.

    • K. M. Backes
    • , D. A. Palken
    •  & H. Wang
  • Article |

    Two logical qubits are encoded in ensembles of four physical qubits through the surface code, then entangled by lattice surgery, which is a protocol for carrying out fault-tolerant operations.

    • Alexander Erhard
    • , Hendrik Poulsen Nautrup
    •  & Thomas Monz
  • Article |

    A chip-scale platform is developed for the conversion of a single microwave excitation of a superconducting qubit into optical photons, with potential uses in quantum computer networks.

    • Mohammad Mirhosseini
    • , Alp Sipahigil
    •  & Oskar Painter
  • 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 |

    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 |

    Scalable optics co-fabricated with a cryogenic surface-electrode ion trap are used to drive high-fidelity multi-ion quantum logic gates, demonstrating a route to simultaneously scale and reduce errors in quantum processors.

    • Karan K. Mehta
    • , Chi Zhang
    •  & Jonathan P. Home
  • Article |

    A surface-electrode ion-trap chip is demonstrated, which delivers all the wavelengths of light required for the preparation and operation of ion qubits.

    • R. J. Niffenegger
    • , J. Stuart
    •  & J. Chiaverini
  • Article |

    An ultimately thin microwave bolometric sensor based on a superconductor–graphene–superconductor Josephson junction with monolayer graphene has a sensitivity approaching the fundamental limit imposed by intrinsic thermal fluctuations.

    • Gil-Ho Lee
    • , Dmitri K. Efetov
    •  & Kin Chung Fong