Volume 9 Issue 2, February 2013

Volume 9 Issue 2

Linear-stability measures for assessing the state of a dynamical system are inherently local, and thus insufficient to quantify stability against substantial perturbations. The volume of a state's basin of attraction offers a powerful alternative — and points toward a plausible explanation for regularity in real-world networks. Letter p89; News & Views p69 IMAGE: PETER J. MENCK COVER DESIGN: ALLEN BEATTIE

Editorials

  • Editorial |

    Funding schemes are set to promote the transfer of lab research into marketable technology.

  • Editorial |

    Nature Physics is now available in an iPad app.

Thesis

Research Highlights

News and Views

  • News & Views |

    Spin coherence of valence holes in semiconductor quantum-dots is governed by interactions with the nuclear spins of the dot lattice. Experiments and theory have revealed an important new ingredient that determines the strength and sign of this coupling.

    • Bernhard Urbaszek
  • News & Views |

    In superconductors spin and charge can be completely decoupled leading to unusual transport phenomena, such as nearly chargeless spin flow.

    • Nadya Mason
    •  & Martin Stehno
  • News & Views |

    Superfluid ultracold gases in designer potentials are analogous to superconducting electronic circuits. The study of these systems refines our understanding of flow and dissipation in quantum fluids, and has applications for inertial sensing and metrology.

    • Mark Edwards
  • News & Views |

    Techniques for understanding how a system responds to an infinitesimal perturbation are well developed — but what happens when the kick gets stronger? Insight into the topology of phase space may now provide the answer.

    • Avi Gozolchiani
    •  & Shlomo Havlin

Letters

  • Letter |

    The elusive effects of quantum gravity could be betrayed by subtle deviations from standard quantum mechanics. An experiment using the gravitational wave bar detector AURIGA explores the limits of quantum gravity-induced modifications in the ground state of a mechanical oscillator cooled to the sub-millikelvin regime.

    • Francesco Marin
    • , Francesco Marino
    • , Michele Bonaldi
    • , Massimo Cerdonio
    • , Livia Conti
    • , Paolo Falferi
    • , Renato Mezzena
    • , Antonello Ortolan
    • , Giovanni A. Prodi
    • , Luca Taffarello
    • , Gabriele Vedovato
    • , Andrea Vinante
    •  & Jean-Pierre Zendri
  • Letter |

    Quantum dots are a promising host for spin-based qubits. Whereas nuclear-field fluctuations adversely affect electron-spin coherence, the smaller hyperfine interaction between holes and nuclei makes holes a promising alternative. A sensitive measurement of the hyperfine constant of the holes in different quantum-dot material systems now demonstrates how this interaction can be tuned and perhaps further reduced.

    • E. A. Chekhovich
    • , M. M. Glazov
    • , A. B. Krysa
    • , M. Hopkinson
    • , P. Senellart
    • , A. Lemaître
    • , M. S. Skolnick
    •  & A. I. Tartakovskii
  • Letter |

    Injection of spin-polarized electrons into a superconductor leads to both spin and charge imbalance. If charge relaxation occurs faster than spin relaxation, it is possible to observe excess spin at almost no extra charge.

    • C. H. L. Quay
    • , D. Chevallier
    • , C. Bena
    •  & M. Aprili
  • Letter |

    Linear-stability measures for assessing the state of a dynamical system are inherently local, and thus insufficient to quantify stability against substantial perturbations. The volume of a state’s basin of attraction offers a powerful alternative—and points towards a plausible explanation for regularity in real-world networks.

    • Peter J. Menck
    • , Jobst Heitzig
    • , Norbert Marwan
    •  & Jürgen Kurths

Articles

  • Article |

    The Efimov effect is a universal phenomenon displaying an infinite tower of three-body bound states. Recently it was observed in an ultracold atomic gas, and now Efimov physics has been predicted to exist in a quantum magnet.

    • Yusuke Nishida
    • , Yasuyuki Kato
    •  & Cristian D. Batista
  • Article |

    Topological insulators are now shown to be protected not only by time-reversal symmetry, but also by crystal lattice symmetry. By accounting for the crystalline symmetries, additional topological insulators can be predicted.

    • Robert-Jan Slager
    • , Andrej Mesaros
    • , Vladimir Juričić
    •  & Jan Zaanen
  • Article |

    A time-dependent study of the effective temperature of carriers in impurity-free graphene now indicates that a disorder-assisted mechanism is responsible for cooling hot electrons. Observation of this so-called supercollision contradicts the idea that electron–phonon interactions dominate cooling.

    • Matt W. Graham
    • , Su-Fei Shi
    • , Daniel C. Ralph
    • , Jiwoong Park
    •  & Paul L. McEuen
  • Article |

    Charge transport is usually limited by collisions between the carriers, impurities and/or phonons. Collisions involving three bodies are generally much rarer. A study now reveals, however, that such supercollisions can play an important role in the properties of graphene.

    • A. C. Betz
    • , S. H. Jhang
    • , E. Pallecchi
    • , R. Ferreira
    • , G. Fève
    • , J-M. Berroir
    •  & B. Plaçais
  • Article |

    Photosynthesis is remarkably efficient. The transport of optically generated excitons from absorbing pigments, through protein complexes, to reaction centres is nearly perfect. Simulations now uncover the microscopic mechanism that drives this coherent behaviour: interactions between the excitons and the vibrational modes of the pigment-protein complex.

    • A. W. Chin
    • , J. Prior
    • , R. Rosenbach
    • , F. Caycedo-Soler
    • , S. F. Huelga
    •  & M. B. Plenio