Volume 6 Issue 9, September 2010

Volume 6 Issue 9

Symmetry-breaking transitions occur over femtosecond timescales in the solid state. This makes it difficult to study the dynamics that drive such a system from a high-symmetry state to a broken-symmetry state. A triple-pulse femtosecond spectroscopic technique enables the details of the evolution of a symmetry breaking charge-order transition in terbium telluride to be studied with unprecedented temporal resolution. Letter p681; News & Views p639 Cover design by David Shand

Editorials

  • Editorial |

    Dark energy is a prime target in the proposed US astronomy programme.

  • Editorial |

    Significant work in particle physics bears his name, but the list of Nobel winners does not.

Thesis

Research Highlights

News and Views

  • News & Views |

    Solar flares are the most energetic events in our Solar System, but relatively little is known about their contribution to the total energy the Earth receives from the Sun. The detection of a moderate solar flare in the total solar irradiance suggests their impact on the variability of the Sun's output could be larger than expected.

    • Hugh S. Hudson
  • News & Views |

    Broken symmetry is central to understanding the properties and behaviour of many solid-state systems, but the speed with which they occur makes them difficult to study. Using a state-of-the-art ultrafast pump–probe technique, a new study reveals in unprecedented detail the rich variety of phenomena that arise during a symmetry breaking transition.

    • Richard D. Averitt
  • News & Views |

    A revisiting of Heisenberg's uncertainty principle in the light of modern quantum information theory yields a formulation that takes into account the reduction in uncertainty from the point of view of a quantum observer.

    • Andreas Winter
  • News & Views |

    The community of statistical physicists meets every three years on a different continent at the series of STATPHYS conferences to define the state-of-the-art in the field and to outline its possible evolution.

    • Luciano Pietronero
  • News & Views |

    Real-space visualizations of the Pauli exclusion principle in clouds of cold fermions show quantum mechanics at work, and suggest a new tool for measuring nanokelvin temperatures.

    • Zoran Hadzibabic

Review

  • Review Article |

    The surprising discovery of high-temperature superconductivity in a material containing a strong magnet—iron—has led to thousands of publications. By placing all the data in context, it becomes clear what we know and where we are headed.

    • Johnpierre Paglione
    •  & Richard L. Greene

Letters

  • Letter |

    The Heisenberg uncertainty principle bounds the uncertainties about the outcomes of two incompatible measurements on a quantum particle. This bound, however, changes if a memory device is involved that stores quantum information. New work now extends the uncertainty principle to include the case of quantum memories, and should provide a guide for quantum information applications.

    • Mario Berta
    • , Matthias Christandl
    • , Roger Colbeck
    • , Joseph M. Renes
    •  & Renato Renner
  • Letter |

    Quantum non-demolition (QND) measurements interrogate a quantum state without disturbing it. A QND scheme that uses a superconducting circuit to investigate microwave photons trapped in a cavity is now shown. The measurement answers the question: are there exactly N photons in the cavity?

    • B. R. Johnson
    • , M. D. Reed
    • , A. A. Houck
    • , D. I. Schuster
    • , Lev S. Bishop
    • , E. Ginossar
    • , J. M. Gambetta
    • , L. DiCarlo
    • , L. Frunzio
    • , S. M. Girvin
    •  & R. J. Schoelkopf
  • Letter |

    Single nitrogen–vacancy centres in diamond are a prime candidate for implementing scalable quantum information processing at room temperature. Work so far has been focused on using the ground state of these defects, but an experimental study now suggests that the excited state is a promising route to fast gate operation.

    • G. D. Fuchs
    • , V. V. Dobrovitski
    • , D. M. Toyli
    • , F. J. Heremans
    • , C. D. Weis
    • , T. Schenkel
    •  & D. D. Awschalom
  • Letter |

    Experimental data suggest that EtMe3Sb[Pd(dmit)2]2, an organic system with a two-dimensional triangular lattice, undergoes a low-temperature phase transition that is not accompanied by classical antiferromagnetic ordering, hinting towards a hitherto unknown quantum state of matter.

    • T. Itou
    • , A. Oyamada
    • , S. Maegawa
    •  & R. Kato
  • Letter |

    Bosons in an optical lattice are used to simulate the Bose–Hubbard model. If the lattice is disordered, a Bose glass is predicted to exist. Transport measurements in such a lattice provide evidence for a disorder-driven superfluid–insulator transition into a Bose-glass state.

    • M. Pasienski
    • , D. McKay
    • , M. White
    •  & B. DeMarco
  • Letter |

    The speed with which symmetry breaking transitions occur in the solid state makes them difficult to study in the time domain. State-of-the-art pump–probe measurements of the dynamics of charge-density waves in terbium telluride enable the evolution of the symmetry breaking charge-order transition of this system to be studied with unprecedented temporal resolution.

    • Roman Yusupov
    • , Tomaz Mertelj
    • , Viktor V. Kabanov
    • , Serguei Brazovskii
    • , Primoz Kusar
    • , Jiun-Haw Chu
    • , Ian R. Fisher
    •  & Dragan Mihailovic
  • Letter |

    Phase transitions in water are normally classified as first or second order. But in confined quasi-one-dimensional films of water, simulations show that the solid–liquid transition can take place by means of a first-order transition or a continuous one without a distinction between solid and liquid.

    • Sungho Han
    • , M. Y. Choi
    • , Pradeep Kumar
    •  & H. Eugene Stanley
  • Letter |

    Although solar flares are the most energetic events that occur in our Solar System, very little is known about their contribution to the total energy the Earth receives from the Sun. The identification of a measurable signal from a moderate-sized solar flare in total solar irradiance data suggests their impact on the variability of the Sun’s output could be larger than expected.

    • Matthieu Kretzschmar
    • , Thierry Dudok de Wit
    • , Werner Schmutz
    • , Sabri Mekaoui
    • , Jean-François Hochedez
    •  & Steven Dewitte
  • Letter |

    Owing to incomplete data, it is difficult to establish tropical cyclone behaviour over long timescales. However, by considering the total released energy of individual cyclones, it is possible to establish changes of cyclone energy and their connection to climate change.

    • Álvaro Corral
    • , Albert Ossó
    •  & Josep Enric Llebot

Articles

  • Article |

    The properties of electric conductors change markedly once quantum phenomena become relevant. So far, work on quantum coherent electron transport has largely focused on static properties, but new theoretical work now looks at such phenomena in the regime of fast alternating currents.

    • Christophe Mora
    •  & Karyn Le Hur
  • Article |

    At absolute zero temperature, exotic phases of matter can be found near a quantum critical point. If geometric frustration is also present, as happens in columbite, the extra quantum fluctuations lead to five distinct states of matter.

    • SungBin Lee
    • , Ribhu K. Kaul
    •  & Leon Balents
  • Article |

    An optical cavity coupled to a micrometre-sized mechanical resonator offers the opportunity to see quantum effects in relatively large structures. It is now shown that a variety of coupling mechanisms enable investigation of these fascinating systems in a number of different ways.

    • J. C. Sankey
    • , C. Yang
    • , B. M. Zwickl
    • , A. M. Jayich
    •  & J. G. E. Harris

Erratum