Volume 5 Issue 1, January 2009

For the new year, we have a new look.

Economic theory failed to envisage even the possibility of a financial crisis like the present one. A new foundation is needed that takes into account the interplay between heterogeneous agents.

A method for characterizing quantum measurement devices completes the suite of 'tomography techniques', which should enable us to learn all there is to know about a given quantum-physics experiment.

Localized electron spins can be manipulated electrically through electric-dipole spin resonance. The ensemble of mechanisms involved has now been brought under the baton of a unifying theoretical description.

More than 100 years ago, Wilhelm Ostwald predicted that crystalline structures would grow from the melt via a series of unstable states — now this cascade has been observed directly in an inorganic semiconductor.

The ability to manipulate an individual superconducting vortex represents a powerful tool for studying the dynamics of vortices and the superconductors that support them. It could also lead to the development of a new class of fluxon-based electronics.

An algorithm that enables a protein's molecular structure to be determined from the faintest of diffraction patterns could increase the potential of next-generation X-ray sources.

So-called one-way schemes have emerged as a powerful model to describe and implement quantum computation. This article reviews recent progress, highlights connections to other areas of physics and discusses future directions.

In quantum mechanics, measurement has a fundamentally different role than in classical physics. Now a general method has been devised to characterize a quantum measurement device, completing the suite of so-called tomography techniques required to fully specify an experiment.

Transport measurements in a high-temperature superconductor provide evidence that the so-called pseudogap phase ends at a quantum critical point located inside the superconducting dome in the phase diagram of cuprates.

The ability to wiggle and stretch individual superconducting vortices with nanoscale precision enables unprecedented insight into their dynamics and the properties of the superconductor that supports them.

High-resolution angle-resolved photoemission measurements of the Fermi-surface and superconducting gap of high-quality C₆Ca crystals should help resolve the nature of the high-temperature superconducting behaviour of this and related intercalated graphite materials.

Low-temperature thermal-transport measurements of a frustrated organic magnet in which a quantum spin-liquid is believed to exist, suggest that the emergence of this state is accompanied by a spin-gap. This contradicts previous studies conducted at higher temperatures, suggesting that our understanding of this system should be re-evaluated.

An array of superconducting nanocircuits has been designed that provides built-in protection from environmental noises. Such ‘topologically protected’ qubits could lead the way to a scalable architecture for practical quantum computation.

An accurate determination of the size and diffusion length of excitons generated with single-walled nanotubes supports the Wannier–Mott picture of their behaviour, and improves the outlook for the use of nanotubes in optoelectronics and biosensing applications.

Analysis of the ejection of electrons in a plane perpendicular to an incident electron beam reveals unexpected differences between the ionization behaviour of atoms and molecules. For molecules that have nuclei at their centres of mass, the angular distribution of emitted electrons is similar to that of atoms. But for those that don’t, the shape of this distribution is qualitatively different.

An algorithm that reconstructs the structure of an object in flight from the diffraction pattern generated by exposing it to an ultrashort burst of X-rays should enhance the potential of free-electron lasers for studying individual molecules, virus and nanoparticles.

High-resolution electron microscope images collected in real time demonstrates the occurrence of multiple intermediary phases during the crystallization of a metal phosphate. The observations represent the first atomic-scale demonstration of Wilhelm Ostwald’s ‘rule of stages’ proposed over a century ago.

In many real-world processes that can be mapped onto complex networks—from cell signalling to transporting people—communication between distant nodes is surprisingly efficient, considering that no node has a full view of the entire network. A framework sets out to explain why ‘navigability’ is so efficient in these networks.