Volume 12 Issue 12, December 2016

Volume 12 Issue 12

A high-resolution age map of the Milky Way picks out structures that validate the most widely accepted cosmological theory, lambda cold dark matter. The chronographic data are also used to probe the chemodynamical formation history of our Galaxy. Article p1170 IMAGE: VINICIUS M. PLACCO COVER DESIGN: ALLEN BEATTIE

Editorial

  • Editorial |

    Elementary particles are the building blocks of matter, but there is also a zoo of quasiparticles that are crucial for understanding how this matter behaves.

Thesis

Feature

  • Feature |

    Quasiparticles are an extremely useful concept that provides a more intuitive understanding of complex phenomena in many-body physics. As such, they appear in various contexts, linking ideas across different fields and supplying a common language.

    • Liesbeth Venema
    • , Bart Verberck
    • , Iulia Georgescu
    • , Giacomo Prando
    • , Elsa Couderc
    • , Silvia Milana
    • , Maria Maragkou
    • , Lina Persechini
    • , Giulia Pacchioni
    •  & Luke Fleet

Research Highlights

News and Views

  • News & Views |

    Dendritic cells use components of their cytoskeleton to both move and ingest pieces of infected cells. This competition for protein resources can give rise to a complex set of states that may be understood with an advection–diffusion model.

    • Herbert Levine
  • News & Views |

    Direct satellite observations of energy transfer between large and small space plasma scales contribute to our understanding of how matter in the Universe gets hot.

    • Alessandro Retinò

Letters

  • Letter |

    The control of long-range interactions is an essential ingredient for the study of exotic phases of matter using atoms in optical lattices. Such control is demonstrated using Rydberg dressing: the coupling of ground state atoms to Rydberg states.

    • Johannes Zeiher
    • , Rick van Bijnen
    • , Peter Schauß
    • , Sebastian Hild
    • , Jae-yoon Choi
    • , Thomas Pohl
    • , Immanuel Bloch
    •  & Christian Gross
  • Letter |

    The prediction of an antiferromagnetic semimetal that breaks both time-reversal and inversion symmetry but respects their combination could provide a platform for studying the interplay between Dirac fermions and magnetism.

    • Peizhe Tang
    • , Quan Zhou
    • , Gang Xu
    •  & Shou-Cheng Zhang
  • Letter |

    Observations of topological surface states provide strong evidence that MoTe2 is a type-II Weyl semimetal, hosting Weyl fermions that have no counterpart in high-energy physics.

    • Ke Deng
    • , Guoliang Wan
    • , Peng Deng
    • , Kenan Zhang
    • , Shijie Ding
    • , Eryin Wang
    • , Mingzhe Yan
    • , Huaqing Huang
    • , Hongyun Zhang
    • , Zhilin Xu
    • , Jonathan Denlinger
    • , Alexei Fedorov
    • , Haitao Yang
    • , Wenhui Duan
    • , Hong Yao
    • , Yang Wu
    • , Shoushan Fan
    • , Haijun Zhang
    • , Xi Chen
    •  & Shuyun Zhou
  • Letter |

    Images of the second-generation Dirac cones that form when graphene is placed on hexagonal boron nitride show the potential of using superlattices to engineer the electronic band structure of van der Waals heterostructures.

    • Eryin Wang
    • , Xiaobo Lu
    • , Shijie Ding
    • , Wei Yao
    • , Mingzhe Yan
    • , Guoliang Wan
    • , Ke Deng
    • , Shuopei Wang
    • , Guorui Chen
    • , Liguo Ma
    • , Jeil Jung
    • , Alexei V. Fedorov
    • , Yuanbo Zhang
    • , Guangyu Zhang
    •  & Shuyun Zhou
  • Letter |

    The anomalous Hall effect is usually associated with ferromagnets but a large anomalous Hall response can be found in topologically non-trivial half-Heusler antiferromagnets thanks to Berry phase effects associated with symmetry breaking.

    • T. Suzuki
    • , R. Chisnell
    • , A. Devarakonda
    • , Y.-T. Liu
    • , W. Feng
    • , D. Xiao
    • , J. W. Lynn
    •  & J. G. Checkelsky
  • Letter |

    The acoustic analogue of a topological insulator is shown: a metamaterial exhibiting one-way sound transport along its edge. The system — a graphene-like array of stainless-steel rods — is a promising new platform for exploring topological phenomena.

    • Cheng He
    • , Xu Ni
    • , Hao Ge
    • , Xiao-Chen Sun
    • , Yan-Bin Chen
    • , Ming-Hui Lu
    • , Xiao-Ping Liu
    •  & Yan-Feng Chen
  • Letter |

    The response of amorphous solids to external stress is not very well understood. A study now shows that certain glasses, upon decreasing temperature, undergo a phase transition characterized by diverging nonlinear elastic moduli.

    • Giulio Biroli
    •  & Pierfrancesco Urbani
  • Letter |

    A colloidal particle connected to suspensions of motile bacteria forms a model system for studying microscale engines in contact with active baths. The engine outperforms its passive counterparts due to the presence of non-Gaussian fluctuations.

    • Sudeesh Krishnamurthy
    • , Subho Ghosh
    • , Dipankar Chatterji
    • , Rajesh Ganapathy
    •  & A. K. Sood

Articles

  • Article |

    Parity–time symmetry in optics is studied in a warm atomic vapour, where its counterpart, anti-parity–time symmetry, as well as refractionless propagation, can also be observed.

    • Peng Peng
    • , Wanxia Cao
    • , Ce Shen
    • , Weizhi Qu
    • , Jianming Wen
    • , Liang Jiang
    •  & Yanhong Xiao
  • Article |

    Cell motility is typically described as a random walk due to the presence of noise. But a dynamical model suggests that dendritic cells move deterministically, alternating between fast and slow motility, and exhibiting periodic polarity reversals.

    • Ido Lavi
    • , Matthieu Piel
    • , Ana-Maria Lennon-Duménil
    • , Raphaël Voituriez
    •  & Nir S. Gov
  • Article |

    Animals moving in groups are expected to differ from their many-body counterparts in equilibrium. A method based on maximum entropy shows that the interactions in starling flocks rearrange slowly enough to permit an equilibrium description locally.

    • Thierry Mora
    • , Aleksandra M. Walczak
    • , Lorenzo Del Castello
    • , Francesco Ginelli
    • , Stefania Melillo
    • , Leonardo Parisi
    • , Massimiliano Viale
    • , Andrea Cavagna
    •  & Irene Giardina
  • Article |

    Substorms in the Earth’s magnetosphere lead to bright aurorae, releasing energy into the surrounding ionosphere. Ground- and space-based observations now reveal how that energy is dissipated and controlled by strong electric currents.

    • E. V. Panov
    • , W. Baumjohann
    • , R. A. Wolf
    • , R. Nakamura
    • , V. Angelopoulos
    • , J. M. Weygand
    •  & M. V. Kubyshkina
  • Article |

    Processes in (space) plasmas occur on different levels — fluid, ion and electron. Now, from satellite data and simulations, an energy-transfer mechanism between the fluid and ion scales is reported: fluid velocity shear is converted into ion heating.

    • T. W. Moore
    • , K. Nykyri
    •  & A. P. Dimmock
  • Article |

    A high-resolution age map of the Milky Way picks out structures that validate the most widely accepted cosmological theory, lambda cold dark matter. The chronographic data are also used to probe the chemodynamical formation history of our Galaxy.

    • D. Carollo
    • , T. C. Beers
    • , V. M. Placco
    • , R. M. Santucci
    • , P. Denissenkov
    • , P. B. Tissera
    • , G. Lentner
    • , S. Rossi
    • , Y. S. Lee
    •  & J. Tumlinson

Measure for Measure

  • Measure for Measure |

    Every now and then, an extra second is added to an earthly year — a cause for trouble and debate, as Felicitas Arias has been witnessing.

    • Felicitas Arias

Correction