Volume 12 Issue 3, March 2016

Volume 12 Issue 3

Simulated pipe flow is interpreted using an ecological model in which predatory zonal flow preys on turbulence, and laminar flows emulate nutrients – establishing a link between turbulence and the directed percolation universality class.Letter p245; News & Views p204IMAGE: HONG-YAN SHIH, TSUNG-LIN HSIEH, NIGEL GOLDENFELD, NICHOLAS GUTTENBERGCOVER DESIGN: ALLEN BEATTIE

Editorials

  • Editorial |

    Physicists have finally detected gravitational waves, in a triumph of ingenuity and perseverance. And now we need to explain them to the general public.

Commentary

  • Commentary |

    For a problem as complex as turbulence, combining universal concepts from statistical physics with ideas from fluid mechanics has proven indispensable. Three decades since this link was formed, it is still providing food for new thought.

    • Yves Pomeau

    Focus:

Thesis

Research Highlights

News and Views

  • News & Views |

    Intense light pulses irradiating a sample of K3C60 result in dramatic changes of its high-frequency (terahertz) conductivity. Could these be signatures of fleeting superconductivity at 100 K and beyond?

    • Jure Demsar
  • News & Views |

    In the transition from laminar to turbulent pipe flow, puffs of turbulence form, split and decay. The phenomenology and lifetime of these turbulent puffs exhibit population dynamics that also drive predator–prey ecosystems on the edge of extinction.

    • Johannes Knebel
    • , Markus F. Weber
    •  & Erwin Frey

    Focus:

  • News & Views |

    In some two-dimensional materials, there's a puzzling intermediate metallic phase between superconducting and insulating states. Experiments on ultraclean crystalline samples suggest this metallic phase could be bosonic.

    • Philip W. Phillips

Letters

  • Letter |

    Owing to electron localization, two-dimensional materials are not expected to be metallic at low temperatures, but a field-induced quantum metal phase emerges in NbSe2, whose behaviour is consistent with the Bose-metal model.

    • A. W. Tsen
    • , B. Hunt
    • , Y. D. Kim
    • , Z. J. Yuan
    • , S. Jia
    • , R. J. Cava
    • , J. Hone
    • , P. Kim
    • , C. R. Dean
    •  & A. N. Pasupathy
  • Letter |

    Topologically non-trivial states usually emerge from systems with strong spin–orbit coupling, but evidence for such states in the Kondo insulator samarium hexaboride suggests that they can also be driven by strong electron correlations.

    • Yasuyuki Nakajima
    • , Paul Syers
    • , Xiangfeng Wang
    • , Renxiong Wang
    •  & Johnpierre Paglione
  • Letter |

    The detection of a single photon heralds the projection of two remote spins onto a maximally entangled state. This has been demonstrated for quantum-dot hole spins, featuring a fast generation rate that could enable quantum technology applications.

    • Aymeric Delteil
    • , Zhe Sun
    • , Wei-bo Gao
    • , Emre Togan
    • , Stefan Faelt
    •  & Ataç Imamoğlu
  • Letter |

    A neutron scattering study of the quantum magnet BiCu2PO6 demonstrates a phenomenon known as energy-level repulsion, which occurs between a long-lived quasiparticle state and a many-particle continuum.

    • K. W. Plumb
    • , Kyusung Hwang
    • , Y. Qiu
    • , Leland W. Harriger
    • , G. E. Granroth
    • , Alexander I. Kolesnikov
    • , G. J. Shu
    • , F. C. Chou
    • , Ch. Rüegg
    • , Yong Baek Kim
    •  & Young-June Kim
  • Letter |

    Quantum liquids at equilibrium follow Fermi liquid theory, but less is known about non-equilibrium conditions. Carbon nanotubes, which exhibit universal scaling behaviour, provide a testbed for many-body physics beyond equilibrium.

    • Meydi Ferrier
    • , Tomonori Arakawa
    • , Tokuro Hata
    • , Ryo Fujiwara
    • , Raphaëlle Delagrange
    • , Raphaël Weil
    • , Richard Deblock
    • , Rui Sakano
    • , Akira Oguri
    •  & Kensuke Kobayashi
  • Letter |

    When laser light is focused onto graphene devices in a magnetic field a long-range photo-Nernst effect causes photocurrents to be generated along the free edges.

    • Helin Cao
    • , Grant Aivazian
    • , Zaiyao Fei
    • , Jason Ross
    • , David H. Cobden
    •  & Xiaodong Xu
  • Letter |

    Experiments and simulations of the transition to turbulence in fluid flow through a quasi-2D channel reveal critical exponents consistent with directed percolation — long conjectured to be the universality class associated with the transition.

    • Masaki Sano
    •  & Keiichi Tamai

    Focus:

  • Letter |

    Fluctuations in the profile of the ocean floor can lead to large variations in tsunami wave height. A theory linking this behaviour to the branched flow characteristics of electron waves through semiconductors may provide a framework for prediction.

    • Henri Degueldre
    • , Jakob J. Metzger
    • , Theo Geisel
    •  & Ragnar Fleischmann
  • Letter |

    Merging magnetic flux ropes, which are believed to play an important role in magnetic reconnection, have now been clearly identified. Observations show that coalescence is indeed closely related to reconnection dynamics and also to turbulence.

    • Rongsheng Wang
    • , Quanming Lu
    • , Rumi Nakamura
    • , Can Huang
    • , Aimin Du
    • , Fan Guo
    • , Waileong Teh
    • , Mingyu Wu
    • , San Lu
    •  & Shui Wang
  • Letter |

    Cassini’s encounter with Saturn’s magnetotail — the long magnetosphere region stretching into space — has revealed that plasma exits the magnetosphere through long-duration magnetic reconnection, which ejects ten times more mass than estimated.

    • C. S. Arridge
    • , J. P. Eastwood
    • , C. M. Jackman
    • , G.-K. Poh
    • , J. A. Slavin
    • , M. F. Thomsen
    • , N. André
    • , X. Jia
    • , A. Kidder
    • , L. Lamy
    • , A. Radioti
    • , D. B. Reisenfeld
    • , N. Sergis
    • , M. Volwerk
    • , A. P. Walsh
    • , P. Zarka
    • , A. J. Coates
    •  & M. K. Dougherty

Articles

  • Article |

    A series of transport experiments on lanthanum antimonide reveal a plateau in its resistivity and an extremely large magnetoresistance that are consistent with topologically protected electronic states.

    • F. F. Tafti
    • , Q. D. Gibson
    • , S. K. Kushwaha
    • , N. Haldolaarachchige
    •  & R. J. Cava
  • Article |

    A study of robots jumping on granular media reveals that performance depends on an added-mass effect born of grains solidifying on impact. Techniques that are optimized for launching off hard surfaces are shown to be compromised by the effect.

    • Jeffrey Aguilar
    •  & Daniel I. Goldman

Measure for Measure

  • Measure for Measure |

    François Piquemal tells the story of the ampere, which bridges mechanical and electromagnetic units.

    • François Piquemal