Nature Physics August Issue

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Submit your next paper to Scientific Reports.   Editorial Top Quo vadis, NASA? p587 doi:10.1038/nphys2068 NASA's space shuttle programme is at an end — as may be the funding for its next space telescope. Full Text | PDF Thesis Top Differentiating the discontinuous p589 Mark Buchanan doi:10.1038/nphys2060 Full Text | PDF Research Highlights Top Our choice from the recent literature p590 doi:10.1038/nphys2065 Full Text | PDF News and Views Top Single-molecule experiments: Out of equilibrium pp591 - 592 Christopher Jarzynski doi:10.1038/nphys2054 Equilibrium free-energy landscapes supply important information about complex molecules such as nucleic acids and proteins. But can equilibrium landscapes be calculated from measurements on a non-equilibrium system? Full Text | PDF See also: Letter by Gupta et al. Planetary science: The Trojan is out there p592 Alison Wright doi:10.1038/nphys2061 Full Text | PDF Quantum gases: An insulating mix p593 Kai Dieckmann doi:10.1038/nphys2059 In a Mott insulator, repulsive interactions suppress conductivity. Such behaviour has been demonstrated, individually, for both bosonic and fermionic atoms in optical lattices. Now, a Bose-Fermi mixture is found to be Mott insulating too, even when the individual components are not. Full Text | PDF See also: Article by Sugawa et al. Superconducting devices: Quantum cups and balls pp594 - 595 P.-M. Billangeon and Y. Nakamura doi:10.1038/nphys2062 A single microwave photon in a superposition of two states of different frequency is now demonstrated using a superconducting quantum interference device to mediate the coupling between two harmonics of a resonator. Such quantum circuits bring closer the possibility of controlling photon-photon interactions at the single-photon level. Full Text | PDF See also: Letter by Zakka-Bajjani et al. Aerodynamics: Bird's eye view p595 Andreas Trabesinger doi:10.1038/nphys2064 Full Text | PDF Graphene: Trilayers unravelled pp596 - 597 Marcus Freitag doi:10.1038/nphys2032 The linear and hyperbolic electronic bands of single- and bilayer graphene give rise to quantum Hall effects that are different from those seen in previously studied 2D systems. The electronic structure of trilayer graphene includes both types of band, giving rise to even richer behaviour. Full Text | PDF See also: Letter by Taychatanapat et al. Physics JOBS of the week Research Engineer University of Surrey / Surrey County Council Kingston, United Kingdom PhD Studentship in physics Physics department, Imperial College London, United Kingdom Independent Research Fellows University of Manchester Manchester, United Kingdom Postdoc Position (M / F) in Medical Systems Biology DKFZ, Deutsches Krebsforschungs- zentrum Heidelberg, Baden-Wuerttemberg, Germany Chair in Climate Physics / Director of Earth Observation and Climate Processes Imperial College London London, United Kingdom More Science jobs from Physics EVENT Emergent Magnetic Monopoles in Frustrated Magnetic Systems 17 October - 18 October 2011 London, UK More science events from Letters Top Quantum superposition of a single microwave photon in two different 'colour' states pp599 - 603 Eva Zakka-Bajjani, Francois Nguyen, Minhyea Lee, Leila R. Vale, Raymond W. Simmonds and José Aumentado doi:10.1038/nphys2035 A single microwave photon is prepared in a superposition of two states of different frequency. This is achieved by using a superconducting quantum interference device to mediate the coupling between two harmonics of a superconducting resonator. First paragraph | Full Text | PDF See also: News and Views by Billangeon & Nakamura Cavity-aided magnetic resonance microscopy of atomic transport in optical lattices pp604 - 607 Nathan Brahms, Thomas P. Purdy, Daniel W. C. Brooks, Thierry Botter and Dan M. Stamper-Kurn doi:10.1038/nphys1967 The power of magnetic resonance imaging for investigating physical and biological systems is well established. Here, it is shown how the sensitivity of cavity atom optics, together with the control provided by atom chips, enables the implementation of a magnetic-resonance-imaging technique that provides a minimally destructive, state-sensitive detection modality for atoms in ultracold gases. First paragraph | Full Text | PDF Twin-atom beams pp608 - 611 Robert Bücker, Julian Grond, Stephanie Manz, Tarik Berrada, Thomas Betz, Christian Koller, Ulrich Hohenester, Thorsten Schumm, Aurélien Perrin and Jorg Schmiedmayer doi:10.1038/nphys1992 Twin photons — pairs of highly correlated photons — are one of the building blocks for quantum optics, and are used in both fundamental tests of quantum physics and technological applications. Now an efficient source for correlated atom pairs is demonstrated, promising to enable a wide range of experiments in the field of quantum matter-wave optics. First paragraph | Full Text | PDF Time-resolved imaging of purely valence-electron dynamics during a chemical reaction pp612 - 615 Paul Hockett, Christer Z. Bisgaard, Owen J. Clarkin and Albert Stolow doi:10.1038/nphys1980 The study of many fundamental processes in chemistry relies on the understanding of the dynamics of the valence electrons, which make and break chemical bonds. A laser method now provides direct information on the dynamics of the valence electrons—separate from any vibrational motion—during a polyatomic chemical reaction, without the need for strong laser fields that unavoidably influence the motions of these electrons. First paragraph | Full Text | PDF Spatially resolving edge states of chiral graphene nanoribbons pp616 - 620 Chenggang Tao, Liying Jiao, Oleg V. Yazyev, Yen-Chia Chen, Juanjuan Feng, Xiaowei Zhang, Rodrigo B. Capaz, James M. Tour, Alex Zettl, Steven G. Louie, Hongjie Dai and Michael F. Crommie doi:10.1038/nphys1991 Edge effects matter in graphene, particularly in nanoribbons. A study using scanning tunnelling microscopy and spectroscopy reveals how chirality at the atomically well-defined edges of a graphene nanoribbon affects its electronic structure. First paragraph | Full Text | PDF Quantum Hall effect and Landau-level crossing of Dirac fermions in trilayer graphene pp621 - 625 Thiti Taychatanapat, Kenji Watanabe, Takashi Taniguchi and Pablo Jarillo-Herrero doi:10.1038/nphys2008 The charge carriers in single-layer graphene are effectively massless. In bilayer graphene, they are massive. In trilayer graphene, the two types coexist, which leads to an unusual quantum Hall response in which the Landau levels of massless and massive charge carriers repeatedly cross. First paragraph | Full Text | PDF See also: News and Views by Freitag Vertical-current-induced domain-wall motion in MgO-based magnetic tunnel junctions with low current densities pp626 - 630 A. Chanthbouala, R. Matsumoto, J. Grollier, V. Cros, A. Anane, A. Fert, A. V. Khvalkovskiy, K. A. Zvezdin, K. Nishimura, Y. Nagamine, H. Maehara, K. Tsunekawa, A. Fukushima and S. Yuasa doi:10.1038/nphys1968 In the past few years, there have been a number of proposals for fabricating magnetic memories based on the current-induced motion of magnetic domain walls. A device that uses a novel geometry for injecting electrical currents into the sample is shown to work with current densities that are two orders of magnitude lower than in previous approaches. First paragraph | Full Text | PDF Experimental validation of free-energy-landscape reconstruction from non-equilibrium single-molecule force spectroscopy measurements pp631 - 634 Amar Nath Gupta, Abhilash Vincent, Krishna Neupane, Hao Yu, Feng Wang and Michael T. Woodside doi:10.1038/nphys2022 The energy-landscape theory is an important tool for investigating how proteins fold. Hummer and Szabo conceived a simple method for constructing folding-energy landscapes from single-molecule pulling experiments. But are these non-equilibrium measurements a valid approach to equilibrium landscapes? The Hummer-Szabo formalism is now experimentally validated for the first time. First paragraph | Full Text | PDF See also: News and Views by Jarzynski Articles Top Hydrodynamic nucleation of quantized vortex pairs in a polariton quantum fluid pp635 - 641 Gaël Nardin, Gabriele Grosso, Yoan Léger, Barbara Piȩtka, François Morier-Genoud and Benoît Deveaud-Plédran doi:10.1038/nphys1959 Exciton-polariton fluids—which are composed of composite light-matter bosons—provide an experimental means for studying quantum fluids that are intrinsically out of equilibrium. These authors demonstrate the nucleation and dynamics of vortex-anti-vortex pairs in the flow of exciton-polaritons passing around an obstacle, and establish these systems as a platform for studying quantum turbulence. Abstract | Full Text | PDF Interaction and filling-induced quantum phases of dual Mott insulators of bosons and fermions pp642 - 648 Seiji Sugawa, Kensuke Inaba, Shintaro Taie, Rekishu Yamazaki, Makoto Yamashita and Yoshiro Takahashi doi:10.1038/nphys2028 In a Mott insulator, strong repulsive interactions suppress conductivity. Such behaviour has been demonstrated, individually, for both bosonic and fermionic atoms confined to optical lattices. Now, a dual Mott insulator of bosons and fermions has been realized, and interspecies interaction are found to markedly modify each Mott insulator. Abstract | Full Text | PDF See also: News and Views by Dieckmann Microscopic polarization in bilayer graphene pp649 - 655 Gregory M. Rutter, Suyong Jung, Nikolai N. Klimov, David B. Newell, Nikolai B. Zhitenev and Joseph A. Stroscio doi:10.1038/nphys1988 Its tunable energy bandgap makes bilayer graphene interesting both from a theoretical perspective and with a view to applications. But exactly how the bandgap is formed is still unclear. A scanning tunnelling spectroscopy study now finds that the microscopic picture of the gap is fundamentally different from what is expected from macroscopic measurements and currently developed theories. Abstract | Full Text | PDF Controlled near-field enhanced electron acceleration from dielectric nanospheres with intense few-cycle laser fields pp656 - 662 Sergey Zherebtsov, Thomas Fennel, Jürgen Plenge, Egill Antonsson, Irina Znakovskaya, Adrian Wirth, Oliver Herrwerth, Frederik Süßmann, Christian Peltz, Izhar Ahmad, Sergei A. Trushin, Vladimir Pervak, Stefan Karsch, Marc J. J. Vrakking, Burkhard Langer, Christina Graf, Mark I. Stockman, Ferenc Krausz, Eckart Ruhl and Matthias F. Kling doi:10.1038/nphys1983 A demonstration of attosecond control of the motion and directed emission of electrons from individual silica nanoparticles using few-cycle laser fields opens new possibilities to manipulate electronic processes in nanoscale systems. Abstract | Full Text | PDF Top Advertisement Scientific American monthly table of contents e-alerts Sign up today! Scientific American has been reporting on unique insights about inspiring developments in science and technology for more than 165 years. With an expertise for pinpointing emerging trends, in every issue Scientific American provides a greater understanding of current events and issues worldwide. The Scientific American monthly table of contents e-alerts provides you with an overview of what is published in the latest issue. 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