Articles in 2011

Topological defects are encountered in fields ranging from condensed-matter physics to cosmology. These broken-symmetry objects are intrinsically local, but theoretical work now suggests that non-local quantum superpositions of such local defects might arise in a quantum phase transition.

So-called topological defects appear in various forms, be it as monopoles, cosmic strings, vortex lines or domain walls. This work suggests that such localized entities can be put in non-local superpositions, and describes the decoherence behaviour of such quantum states.

An optical technique based on Doppler velocimetry reveals important aspects of the physics underlying the propagation of spin polarization in a two-dimensional electron gas. The spin mobility is shown to track the high electron mobility, but coherent spin precession is lost at temperatures near 150 K, posing a challenge for future spintronics devices.

An optically trapped colloidal particle serves as the first realization of a stochastic thermal engine, extending our understanding of the thermodynamics behind the Carnot cycle to microscopic scales where fluctuations dominate.

It has long been debated whether it is possible to approach a zero-temperature metallic state in a two-dimensional system. A study of the electrical characteristics of arrays of superconducting islands of varying thickness and spacing on a normal metal film suggests it is.

When an intense laser pulse hits a flat metal foil, it ejects a spray of high-energy protons. Laser irradiation of a curved foil covering the tip of a hollow cone focuses the protons to intensities that could be useful for generating extreme states of matter.

Electromagnons are excitations that exhibit both electric and magnetic dipole moments, and are expected to enhance the coupling of magnetization and polarization in multiferroic materials. The identification of electromagnons in a perovskite helimagent may be useful in the development of ways to manipulate light.

Investment in science must be part of Europe's plan to rebuild its economies.

The Higgs boson is running out of places to hide.

An open quantum system loses its 'quantumness' when information about the state leaks into its surroundings. Researchers now show how this decoherence can be controlled between two incompatible regimes in the case of a single photon.

The realization that primordial black holes produce oscillations when they pass through stars brings us one step closer to observing traces of this dark-matter candidate that formed in the early Universe.