Table of contents

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Big in Japan p527


Welcome to J-PARC, Japan's new accelerator facility.



A cook's tale pp529 - 530

Paul C. Canfield


The design and synthesis of novel materials is the rubric of both haute cuisine and materials physics — and in both there is great pleasure in creating and sharing the results of a new recipe.



Collectivist revolution in evolution p531

Mark Buchanan



Research Highlights

Research highlights p532



News and Views

Few-body physics: Giant trimers true to scale pp533 - 534

Vitaly Efimov


Quantum mechanics predicts an infinite series of loosely bound states of three bosons, and the size of these trimers should scale with a factor of 22.7. This general result seems to be confirmed now in an experiment with an ultracold gas of potassium atoms.

Subject Categories: Atomic and molecular physics | Quantum physics

See also: Article by Zaccanti et al.

Supersolid helium: Stiffer but flowing pp534 - 535

Sébastien Balibar


There is growing evidence that solid helium-4 possesses superfluid properties, but the nature of this paradoxical phenomenon remains mysterious. The finding that helium-4 in its 'supersolid' form is stiffer than the normal solid adds to the enigma.

Subject Categories: Condensed-matter physics | Statistical physics, thermodynamics and nonlinear dynamics

See also: Article by West et al.

Lunar science: In the Moon's wake p535

David Gevaux


Subject Category: Astrophysics

Cell migration: Going my way? pp536 - 537

Joel Voldman


That ratchet-shaped structures patterned on a surface can direct the otherwise random motion of living cells across it is perhaps unsurprising. But that the direction of this motion depends on the type of cell is remarkable and potentially useful.

Subject Categories: Biological physics | Fluid dynamics

See also: Article by Mahmud et al.

Astrophysics: A happy medium pp537 - 538

M. Coleman Miller


The case for the existence of intermediate-mass black holes, hundreds to thousands of times more massive than our Sun, has received a major boost — with implications for gravitational waves and clustered star formation.

Subject Category: Astrophysics

Atom chips: Read the labels pp538 - 539

Chris Westbrook


Compact interferometers that exploit the wave character of atoms have the potential to outpace their optical counterparts in a number of sensing applications. A technique that harnesses the internal structure of atoms should bring such applications a step closer.

Subject Categories: Atomic and molecular physics | Quantum physics | Techniques and instrumentation

See also: Article by Böhi et al.



Quantum error correction beyond qubits pp541 - 546

Takao Aoki, Go Takahashi, Tadashi Kajiya, Jun-ichi Yoshikawa, Samuel L. Braunstein, Peter van Loock & Akira Furusawa


As with any viable technology, quantum-information processors have to deal with imperfections. The experimental implementation of a quantum-error correction code indicates how imperfections can be handled in a system where quantum information is encoded in continuous variables.

Subject Categories: Quantum physics | Optical physics

Engineering the quantum transport of atomic wavefunctions over macroscopic distances pp547 - 550

A. Alberti, V. V. Ivanov, G. M. Tino & G. Ferrari


How far can you stretch an atomic wavefunction? An experiment demonstrates that the wavefunction of an ensemble of ultracold atoms trapped in an optical lattice can be reversibly expanded and shrunk over a distance of 1.5 mm.

Subject Categories: Atomic and molecular physics | Quantum physics

Stylus ion trap for enhanced access and sensing pp551 - 554

Robert Maiwald, Dietrich Leibfried, Joe Britton, James C. Bergquist, Gerd Leuchs & David J. Wineland


An ion trap has been built and characterized in which the atom sits on the top of a stylus-like electrode. The design should find application in the construction of efficient light–matter interfaces and field sensors, where good access to the ion is crucial.

Subject Categories: Atomic and molecular physics | Techniques and instrumentation | Quantum physics

Spin waves and magnetic exchange interactions in CaFe2As2 pp555 - 560

Jun Zhao, D. T. Adroja, Dao-Xin Yao, R. Bewley, Shiliang Li, X. F. Wang, G. Wu, X. H. Chen, Jiangping Hu & Pengcheng Dai


It is likely that antiferromagnetism has a role in the superconductivity of iron arsenide. But is the magnetism local, as described by the Heisenberg model, or itinerant, which is more in agreement with the Stoner model? The answer is both.

Subject Categories: Condensed-matter physics | Materials physics

Measurement of single-molecule frictional dissipation in a prototypical nanoscale system pp561 - 564

H. Hedgeland, P. Fouquet, A. P. Jardine, G. Alexandrowicz, W. Allison & J. Ellis


A picosecond technique for measuring the kinetic friction of a single benzene molecule on graphite reveals continuous Brownian motion, rather than the jerky hopping observed on most other surfaces.

Subject Categories: Nanotechnology | Atomic and molecular physics | Techniques and instrumentation

Appearance of a fractional Stokes–Einstein relation in water and a structural interpretation of its onset pp565 - 569

Limei Xu, Francesco Mallamace, Zhenyu Yan, Francis W. Starr, Sergey V. Buldyrev & H. Eugene Stanley


The Stokes–Einstein equation relates the self-diffusion constant of a liquid with the mobility of its constituents. In water, however, the relation has to be modified for temperatures below approx290 K. A combined experimental and numerical investigation suggests that this behaviour results from a specific change in the local water structure.

Subject Categories: Condensed-matter physics | Statistical physics, thermodynamics and nonlinear dynamics

Self-organized helical equilibria as a new paradigm for ohmically heated fusion plasmas pp570 - 574

R. Lorenzini, E. Martines, P. Piovesan, D. Terranova, P. Zanca, M. Zuin, A. Alfier, D. Bonfiglio, F. Bonomo, A. Canton, S. Cappello, L. Carraro, R. Cavazzana, D. F. Escande, A. Fassina, P. Franz, M. Gobbin, P. Innocente, L. Marrelli, R. Pasqualotto, M. E. Puiatti, M. Spolaore, M. Valisa, N. Vianello, P. Martin & RFX-mod team and collaborators


A reversed-field pinch is a toroidal device for magnetically confining plasmas, and a potential alternative to the tokamak for a future fusion reactor. Observations of the evolution of a reversed-field-pinch plasma towards a self-organized single-helicity state suggest that instability problems, which have previously hindered the development of these devices, could now be overcome.

Subject Category: Plasma physics



Field-sensitive addressing and control of field-insensitive neutral-atom qubits pp575 - 580

N. Lundblad, J. M. Obrecht, I. B. Spielman & J. V. Porto


A quantum computer requires quantum systems that are well-isolated from external perturbations, but which can still be easily manipulated with external fields. A scheme that uses spatially inhomogeneous fields to selectively address neutral-atom qubits while they are in field-insensitive superposition states satisfies these competing needs.

Subject Categories: Atomic and molecular physics | Quantum physics | Techniques and instrumentation

Observation of electric-field-induced Cs Rydberg atom macrodimers pp581 - 585

K. R. Overstreet, A. Schwettmann, J. Tallant, D. Booth & J. P. Shaffer


Bound macrodimers have now been directly observed for the first time. Macrodimers comprise two Rydberg atoms with a separation as large as 9 mum. The unique properties of macrodimers mean that they enable new experiments for investigating ultracold gases.

Subject Category: Atomic and molecular physics

Observation of an Efimov spectrum in an atomic system pp586 - 591

M. Zaccanti, B. Deissler, C. D'Errico, M. Fattori, M. Jona-Lasinio, S. Müller, G. Roati, M. Inguscio & G. Modugno


In 1970, Vitaly Efimov predicted that three interacting particles can form an infinite series of bound trimer states, even when none of the two-particle subsystems is stable. Experimental evidence for such an exotic state was obtained in 2006, but now an Efimov spectrum, containing two such states with the predicted scaling between them, has been observed.

Subject Categories: Atomic and molecular physics | Quantum physics

See also: News and Views by Efimov

Coherent manipulation of Bose–Einstein condensates with state-dependent microwave potentials on an atom chip pp592 - 597

Pascal Böhi, Max F. Riedel, Johannes Hoffrogge, Jakob Reichel, Theodor W. Hänsch & Philipp Treutlein


Simultaneous coherent control of internal and motional states of a Bose–Einstein condensate has been demonstrated on an 'atom chip'. The method should provide a route to generating many-particle entangled states, which are needed for entanglement-based technologies such as quantum-information processing or quantum-enhanced metrology.

Subject Categories: Atomic and molecular physics | Techniques and instrumentation | Atomic and molecular physics

See also: News and Views by Westbrook

Role of shear modulus and statistics in the supersolidity of helium pp598 - 601

Joshua T. West, Oleksandr Syshchenko, John Beamish & Moses H. W. Chan


The first evidence of supersolidity—the potential ability of solids to move without friction—in solid 4He was obtained in torsional-oscillator experiments. But later observations raised the possibility that the characteristic frequency changes were simply due to stiffening of the solid. Now, the results from a series of experiments comparing 3He and 4He rule out that explanation.

Subject Categories: Condensed-matter physics | Statistical physics, thermodynamics and nonlinear dynamics

See also: News and Views by Balibar

Lévy flights of photons in hot atomic vapours pp602 - 605

N. Mercadier, W. Guerin, M. Chevrollier & R. Kaiser


Lévy flights, a form of random walk, are quite common in nature. However only macroscopic signatures, obtained by averaging over many steps, have been measured so far. Now, the individual steps are observed directly as light scatters in a hot atomic vapour.

Subject Category: Optical physics

Directing cell motions on micropatterned ratchets pp606 - 612

Goher Mahmud, Christopher J. Campbell, Kyle J. M. Bishop, Yulia A. Komarova, Oleg Chaga, Siowling Soh, Sabil Huda, Kristiana Kandere-Grzybowska & Bartosz A. Grzybowski


It is not surprising that a microfluidic channel whose walls have a ratchet-like structure can preferentially direct the flow of large particles in one direction. But a study of the movement of living cells through such channels provides the remarkable observation that the direction of preferred motion can be different for different species of cell.

Subject Categories: Biological physics | Fluid dynamics

See also: News and Views by Voldman