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Editorials

Capital investment p61

doi:10.1038/nphys2557

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


App-y days p61

doi:10.1038/nphys2558

Nature Physics is now available in an iPad app.


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Thesis

Going up, going down p63

Mark Buchanan

doi:10.1038/nphys2547


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News and Views

Quantum dots: Reading the signs pp65 - 66

Bernhard Urbaszek

doi:10.1038/nphys2537

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.

Subject terms: Materials physics | Condensed-matter physics | Nanotechnology

See also: Letter by Chekhovich et al.


Solar physics: Magnetic dance p66

Iulia Georgescu

doi:10.1038/nphys2550

Subject terms: Astrophysics | Plasma physics


Superconductors: No charge for spin transport pp67 - 68

Nadya Mason & Martin Stehno

doi:10.1038/nphys2529

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

Subject terms: Condensed-matter physics | Electronics, photonics and device physics

See also: Letter by Quay et al.


Ultracold gases: Atom SQUID pp68 - 69

Mark Edwards

doi:10.1038/nphys2546

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.

Subject terms: Atomic and molecular physics | Quantum physics


Nonlinear dynamics: New tricks for big kicks pp69 - 70

Avi Gozolchiani & Shlomo Havlin

doi:10.1038/nphys2539

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.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics

See also: Letter by Menck et al.


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Letters

Gravitational bar detectors set limits to Planck-scale physics on macroscopic variables pp71 - 73

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

doi:10.1038/nphys2503

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.

Subject terms: Quantum physics | Other physics


Element-sensitive measurement of the hole–nuclear spin interaction in quantum dots pp74 - 78

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

doi:10.1038/nphys2514

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.

Subject terms: Materials physics | Nanotechnology

See also: News and Views by Urbaszek


Thermodynamic phase diagram of static charge order in underdoped YBa2Cu3Oy pp79 - 83

David LeBoeuf, S. Krämer, W. N. Hardy, Ruixing Liang, D. A. Bonn & Cyril Proust

doi:10.1038/nphys2502

A thermodynamic probe of the recently discovered charge-density-wave order in YBa2Cu3Oy reveals a biaxial modulation in magnetic fields up to 40T.

Subject terms: Condensed-matter physics | Materials physics


Spin imbalance and spin-charge separation in a mesoscopic superconductor pp84 - 88

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

doi:10.1038/nphys2518

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.

Subject terms: Condensed-matter physics | Electronics, photonics and device physics

See also: News and Views by Mason & Stehno


How basin stability complements the linear-stability paradigm pp89 - 92

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

doi:10.1038/nphys2516

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.

Subject term: Statistical physics, thermodynamics and nonlinear dynamics

See also: News and Views by Gozolchiani & Havlin


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Articles

Efimov effect in quantum magnets pp93 - 97

Yusuke Nishida, Yasuyuki Kato & Cristian D. Batista

doi:10.1038/nphys2523

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.

Subject terms: Condensed-matter physics | Quantum physics


The space group classification of topological band-insulators pp98 - 102

Robert-Jan Slager, Andrej Mesaros, Vladimir Juričić & Jan Zaanen

doi:10.1038/nphys2513

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.

Subject terms: Condensed-matter physics | Materials physics


Photocurrent measurements of supercollision cooling in graphene pp103 - 108

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

doi:10.1038/nphys2493

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.

Subject terms: Condensed-matter physics | Materials physics


Supercollision cooling in undoped graphene pp109 - 112

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

doi:10.1038/nphys2494

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.

Subject terms: Condensed-matter physics | Materials physics


The role of non-equilibrium vibrational structures in electronic coherence and recoherence in pigment–protein complexes pp113 - 118

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

doi:10.1038/nphys2515

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.

Subject terms: Biological physics | Quantum physics


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