Volume 8 Issue 10, October 2012

Volume 8 Issue 10

Chirality is usually manifested by differences in a material's response to left- and right-circularly polarized light. This difference is the result of the specific distribution of charge within chiral materials. A similar response has now been found to result from the chiral spin structure of an antiferromagnet. Letter p734 COVER IMAGE: DAVID SZALLER AND ISTVAN KÉZSMÁRKI COVER DESIGN: ALLEN BEATTIE

Editorial

  • Editorial |

    The candidates in the forthcoming US presidential election have set out their opinions on scientific issues — but in the shadow of possible swingeing cuts in the science budget.

Correspondence

Thesis

Books and Arts

Research Highlights

News and Views

  • News & Views |

    Faraday and Dirac constructed magnetic monopoles using the practical and mathematical tools available to them. Now physicists have engineered effective monopoles by combining modern optics with nanotechnology. Part matter and part light, these magnetic monopoles travel at unprecedented speeds.

    • Steven T. Bramwell
  • News & Views |

    Devices based on surface electrons in topological insulators are keenly anticipated, but singling these electrons out amid abundant bulk electrons poses a formidable challenge. Inspiration from the common transistor now enables manipulation of these exotic states.

    • L. Andrew Wray
  • News & Views |

    Interfacial instabilities brought on by the penetration of one fluid into another hamper processes such as enhanced oil recovery from porous rock. But these instabilities can be suppressed with a simple gradient in fluid depth — a natural feature of many practical vessel geometries.

    • Anne Juel
  • News & Views |

    Optical vortices usually break up when they propagate through nonlinear media. Now, however, experiments show the helical structure of an infrared beam can survive a high-harmonic-generation process. This could lead to a table-top source of attosecond helical light pulses.

    • Serguei Patchkovskii
    •  & Michael Spanner

Research Article

Letters

  • Letter |

    Shor’s quantum algorithm factorizes integers, and implementing this is a benchmark test in the early development of quantum processors. Researchers now demonstrate this important test in a solid-state system: a circuit made up of four superconducting qubits factorizes the number 15.

    • Erik Lucero
    • , R. Barends
    • , Y. Chen
    • , J. Kelly
    • , M. Mariantoni
    • , A. Megrant
    • , P. O’Malley
    • , D. Sank
    • , A. Vainsencher
    • , J. Wenner
    • , T. White
    • , Y. Yin
    • , A. N. Cleland
    •  & John M. Martinis
  • Letter |

    An analogue of a magnetic monopole is now observed in a condensed state of light–matter hybrid particles known as cavity polaritons. Spin-phase excitations of the polariton fluid are accelerated along the cavity under the influence of a magnetic field—just as if they were single magnetic charges.

    • R. Hivet
    • , H. Flayac
    • , D. D. Solnyshkov
    • , D. Tanese
    • , T. Boulier
    • , D. Andreoli
    • , E. Giacobino
    • , J. Bloch
    • , A. Bramati
    • , G. Malpuech
    •  & A. Amo
  • Letter |

    Doping a topological insulator with manganese makes it magnetic. Moreover, decreasing the concentration of Dirac fermions in a Mn-doped topological insulator with an electric field increases the strength of its magnetic characteristics—a trait that could be valuable to the use of topological insulators in the development of spintronics.

    • Joseph G. Checkelsky
    • , Jianting Ye
    • , Yoshinori Onose
    • , Yoshihiro Iwasa
    •  & Yoshinori Tokura
  • Letter |

    Chirality is usually manifested by differences in a material’s response to left- and right-circularly polarized light. This difference is the result of the specific distribution of charge within chiral materials. A similar response has now been found to result from the chiral spin structure of an antiferromagnet.

    • S. Bordács
    • , I. Kézsmárki
    • , D. Szaller
    • , L. Demkó
    • , N. Kida
    • , H. Murakawa
    • , Y. Onose
    • , R. Shimano
    • , T. Rõõm
    • , U. Nagel
    • , S. Miyahara
    • , N. Furukawa
    •  & Y. Tokura
  • Letter |

    It is known that graphene exhibits natural ripples with characteristic lengths of around 10 nm. But when it is stretched across nanometre-scale trenches that form in a reconstructed copper surface, it develops even tighter corrugations that cannot be explained by continuum theory.

    • Levente Tapasztó
    • , Traian Dumitrică
    • , Sung Jin Kim
    • , Péter Nemes-Incze
    • , Chanyong Hwang
    •  & László P. Biró
  • Letter |

    Optical vortices exhibit a corkscrew-like shape as they travel. The study of this phenomenon, known as singular optics, is now extended to the high-power regime where high-harmonic processes become evident. This type of radiation could help illuminate novel attosecond phenomena in atoms and molecules.

    • M. Zürch
    • , C. Kern
    • , P. Hansinger
    • , A. Dreischuh
    •  & Ch. Spielmann
  • Letter |

    When a low-viscosity fluid penetrates a fluid of higher viscosity confined by parallel plates, finger-like patterns propagate at the interface between the two fluids. Experiments now show that tapering the fluid cell can suppress this instability - providing interfacial control via a simple change in geometry.

    • Talal T. Al-Housseiny
    • , Peichun A. Tsai
    •  & Howard A. Stone

Articles

  • Article |

    Decreasing the doping of a cuprate superconductor below a certain critical value causes its critical temperature to fall, however the reason for this has been unclear. Sensitive measurements of the Nernst effect in yttrium barium copper oxide suggest it is the result of competition with an emerging stripe phase.

    • J. Chang
    • , N. Doiron-Leyraud
    • , O. Cyr-Choinière
    • , G. Grissonnanche
    • , F. Laliberté
    • , E. Hassinger
    • , J-Ph. Reid
    • , R. Daou
    • , S. Pyon
    • , T. Takayama
    • , H. Takagi
    •  & Louis Taillefer
  • Article |

    Spin–orbit interaction induces spin-polarization decay in semiconductor quantum wells. But this decay can be suppressed in favour of a helical spin mode by tuning the interaction. Optical pump–probe measurements provide direct evidence of the resulting helix—a signature that has so far only been inferred from transport measurements.

    • M. P. Walser
    • , C. Reichl
    • , W. Wegscheider
    •  & G. Salis
  • Article |

    When electrons are accelerated to near light-speeds through an overdense plasma by an intense laser beam, the usually opaque plasma becomes optically transparent. High-speed laser experiments provide unprecedented insight into the dynamics of this process.

    • Sasi Palaniyappan
    • , B. Manuel Hegelich
    • , Hui-Chun Wu
    • , Daniel Jung
    • , Donald C. Gautier
    • , Lin Yin
    • , Brian J. Albright
    • , Randall P. Johnson
    • , Tsutomu Shimada
    • , Samuel Letzring
    • , Dustin T. Offermann
    • , Jun Ren
    • , Chengkun Huang
    • , Rainer Hörlein
    • , Brendan Dromey
    • , Juan C. Fernandez
    •  & Rahul C. Shah