Skip to main content

Thank you for visiting You are using a browser version with limited support for CSS. To obtain the best experience, we recommend you use a more up to date browser (or turn off compatibility mode in Internet Explorer). In the meantime, to ensure continued support, we are displaying the site without styles and JavaScript.

Volume 592 Issue 7852, 1 April 2021

Laser-cooled antimatter

Laser cooling — the use of photons to slow the movement of atoms — changed the face of atomic physics when it was first demonstrated 40 years ago. In this week’s issue, the ALPHA collaboration takes this technique into fresh territory by successfully applying it to antimatter. Working at CERN’s Antiproton Decelerator facility, the researchers trapped atoms of antihydrogen using magnetic fields and then irradiated them with carefully tuned pulses of a purpose-built, ultraviolet laser. This slowed some of the atoms down, thereby cooling them and reducing the width of a measured atomic transition in the anti-atoms. The researchers believe the technique should make it easier to investigate the fundamental properties of antimatter — including its gravitational behaviour. The cover shows a close-up of the end electrode of the gold-plated Penning trap that is used to capture and manipulate antiprotons and positrons to form the antihydrogen atoms.

Cover image: Niels Madsen/ALPHA/Swansea Univ.

This Week

News in Focus




    News & Views

  • News & Views |

    A laser beam has been used to slow down antihydrogen atoms, the simplest atoms made of pure antimatter. The technique might enable some fundamental symmetries of the Universe to be probed with exceptionally high precision.

    • Masaki Hori
  • News & Views |

    Resident gut microbes can help to block infection, but the mechanisms involved are not fully understood. It has now been found that changes in the microbial community after infection boost the level of a molecule that combats harmful bacteria.

    • Melissa M. Kendall
    • Vanessa Sperandio
  • News & Views |

    The positions of all the atoms in a sample of a metallic glass have been measured experimentally — fulfilling a decades-old dream for glass scientists, and raising the prospect of fresh insight into the structures of disordered solids.

    • Paul Voyles
  • News & Views |

    The exchange of DNA between pairs of chromosomes is key to sexual reproduction. It emerges that one step in this process — the introduction of DNA breaks by the enzyme Spo11 — relies on condensation of proteins into liquid-like droplets.

    • Kevin D. Corbett
  • Articles

  • 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 |

    A 3D-printing strategy involving jets of charged aerosol particles guided by electric-field lines allows direct deposition of various metal nanostructures, including helices, letters and vertical split-ring resonator structures.

    • Wooik Jung
    • Yoon-Ho Jung
    • Mansoo Choi
  • Article |

    Phylogenies of human placental cells based on whole-genome sequencing of bulk samples and microdissections reveal extensive mutagenesis in placental tissue, and suggest that mosaicism is a typical part of normal placental development.

    • Tim H. H. Coorens
    • Thomas R. W. Oliver
    • Sam Behjati
  • Article |

    A large, open dataset containing parallel recordings from six visual cortical and two thalamic areas of the mouse brain is presented, from which the relative timing of activity in response to visual stimuli and behaviour is used to construct a hierarchy scheme that corresponds to anatomical connectivity data.

    • Joshua H. Siegle
    • Xiaoxuan Jia
    • Christof Koch
  • Article |

    In a rat model of short bowel syndrome, transplantation of small intestinal organoids into the colon partially restores intestinal function and improves survival—a proof of principle that organoid transplantation might have therapeutic benefit.

    • Shinya Sugimoto
    • Eiji Kobayashi
    • Toshiro Sato
  • Article |

    The SARS-CoV-2 variant expressing spike(D641G) shows increased infectivity in human lung epithelial cells and in hamster and primary human upper airway tissues, but is more susceptible to neutralization by antibodies raised against SARS-CoV-2.

    • Jessica A. Plante
    • Yang Liu
    • Pei-Yong Shi
  • Article |

    A SARS-CoV-2 variant containing a D614G substitution in the spike protein shows enhanced binding to human ACE2, increased replication in human cell cultures and a competitive advantage in animal models of infection.

    • Bin Zhou
    • Tran Thi Nhu Thao
    • Martin Beer
  • Article |

    In studies using mouse models of psoriasis, a spectrum of innate lymphoid cell types is reconfigured and converges via multiple trajectories on a type 3-like state, demonstrating the range and flexibility of innate lymphoid cell responses in the skin.

    • Piotr Bielecki
    • Samantha J. Riesenfeld
    • Richard A. Flavell
  • Article |

    HLA peptidomic analysis identifies recurrent intracellular bacteria-derived peptides presented on HLA-I and HLA-II molecules in melanoma tumours, revealing how bacteria can modulate immune functions and responses to cancer therapies.

    • Shelly Kalaora
    • Adi Nagler
    • Yardena Samuels

Amendments & Corrections

Nature Outlook

  • Nature Outlook |

    Sports science

    Behind every athlete at this year’s Olympic Games stands a team of scientists tasked with ensuring competitors can safely perform to the limit of their ability. From developing training techniques to protecting sporting integrity, science has never been so important in elite sport.

Nature Briefing

Sign up for the Nature Briefing newsletter — what matters in science, free to your inbox daily.

Get the most important science stories of the day, free in your inbox. Sign up for Nature Briefing


Quick links