Volume 8 Issue 6, June 2012

Volume 8 Issue 6

The proximity effect enables the injection of Cooper pairs from a superconductor into a normal metal, but they usually don't travel far into the metal. A study of the propagation of Cooper pairs from irregularly shaped superconducting islands on a metal film reveals that the pairs can travel further than expected for certain island geometries. Letter p464 IMAGE: JUNGDAE KIM, GREG FIETE AND CHIH-KANG SHIHCOVER DESIGN: ALLEN BEATTIE

Editorial

  • Editorial |

    Proposed UK libel-law reform is good news for the process of science, but a proposed constitutional reform may not be good for the profile of science.

Thesis

Books and Arts

Research Highlights

News and Views

  • News & Views |

    Do quantum states offer a faithful representation of reality or merely encode the partial knowledge of the experimenter? A new theorem illustrates how the latter can lead to a contradiction with quantum mechanics.

    • Scott Aaronson
  • News & Views |

    Modern optics enables precision control over the laser field entering a nonlinear optical crystal. This has made it possible to realize a classical analogue of Bose–Einstein condensation, and it could provide a means of exerting microscopic control over the macroscopic state of complex systems.

    • Claudio Conti
  • News & Views |

    The quantum spin Hall effect is predicted to be the result of two oppositely polarized spin currents travelling in opposite directions around the edges of a topological insulator. But only now has the spin polarization of these currents been confirmed.

    • Yi Zhou
    •  & Fu-Chun Zhang

Letters

  • Letter |

    Bell’s equations enable scientists to test the fundamental implications of quantum physics. A central tenet of this idea is that the choice of measurement is truly random. Researchers now show that some Bell experiments can even increase randomness in cases where choice is not entirely free. The concept could increase the usefulness of weakly random sources for more thorough tests of quantum mechanics.

    • Roger Colbeck
    •  & Renato Renner
  • Letter |

    An interferometric implementation of Young’s double-slit experiment is used to probe quantum correlations that are manifest in the distribution of local spin fluctuations in a two-component degenerate Fermi gas.

    • Jakob Meineke
    • , Jean-Philippe Brantut
    • , David Stadler
    • , Torben Müller
    • , Henning Moritz
    •  & Tilman Esslinger
  • Letter |

    Despite their name, the bulk electrical conductivity of most topological insulators is relatively high, masking many of the important characteristics of its protected, surface conducting states. Counter-doping reduces the bulk conductivity of Bi2Se3 significantly, allowing these surface states and their properties to be clearly identified.

    • Dohun Kim
    • , Sungjae Cho
    • , Nicholas P. Butch
    • , Paul Syers
    • , Kevin Kirshenbaum
    • , Shaffique Adam
    • , Johnpierre Paglione
    •  & Michael S. Fuhrer
  • Letter |

    The proximity effect enables the injection of Cooper pairs from a superconductor into a normal metal, but they usually do not travel far into the metal. A study of the propagation of Cooper pairs from irregularly shaped superconducting islands on a metal film finds that they can travel further than expected for certain island geometries.

    • Jungdae Kim
    • , Victor Chua
    • , Gregory A. Fiete
    • , Hyoungdo Nam
    • , Allan H. MacDonald
    •  & Chih-Kang Shih
  • Letter |

    Bose–Einstein condensation is usually considered to be an inherently quantum mechanical phenomenon. An observation of the condensation in a classical system of light waves in a nonlinear crystal demonstrates that it is a general wave-mechanical phenomenon.

    • Can Sun
    • , Shu Jia
    • , Christopher Barsi
    • , Sergio Rica
    • , Antonio Picozzi
    •  & Jason W. Fleischer

Articles

  • Article |

    A no-go theorem on the reality of the quantum state is demonstrated. If the quantum state merely represents information about the physical state of a system, then predictions that contradict those of quantum theory are obtained.

    • Matthew F. Pusey
    • , Jonathan Barrett
    •  & Terry Rudolph
  • Article |

    In 2000, Asher Peres put forward the paradoxical idea that entanglement could be produced after the entangled particles have been measured, even if they no longer exist. Researchers now experimentally demonstrate this idea using four photons.

    • Xiao-song Ma
    • , Stefan Zotter
    • , Johannes Kofler
    • , Rupert Ursin
    • , Thomas Jennewein
    • , Časlav Brukner
    •  & Anton Zeilinger
  • Article |

    The quantum spin Hall state is predicted to consist of two oppositely polarized spin currents travelling in opposite directions around the edges of a topological insulator. Non-local measurements of the transport in HgTe quantum wells confirm the polarized nature of these edge states.

    • Christoph Brüne
    • , Andreas Roth
    • , Hartmut Buhmann
    • , Ewelina M. Hankiewicz
    • , Laurens W. Molenkamp
    • , Joseph Maciejko
    • , Xiao-Liang Qi
    •  & Shou-Cheng Zhang
  • Article |

    Ferromagnetic resonance excitations offer a means to coherently manipulate the spin dynamics of spintronic devices and systems. A demonstration of the ability to control these excitations with electric fields alone could drastically reduce the power consumption of these devices.

    • Takayuki Nozaki
    • , Yoichi Shiota
    • , Shinji Miwa
    • , Shinichi Murakami
    • , Frédéric Bonell
    • , Shota Ishibashi
    • , Hitoshi Kubota
    • , Kay Yakushiji
    • , Takeshi Saruya
    • , Akio Fukushima
    • , Shinji Yuasa
    • , Teruya Shinjo
    •  & Yoshishige Suzuki
  • Article |

    Small clusters of magnetic atoms can behave in very different ways to those same atoms in bulk. Arranging iron atoms one by one into complex but well-defined patterns on a copper surface enables the construction of nanoscale magnetic structures with tailored characteristics.

    • Alexander Ako Khajetoorians
    • , Jens Wiebe
    • , Bruno Chilian
    • , Samir Lounis
    • , Stefan Blügel
    •  & Roland Wiesendanger

Corrigendum