Letters in 2008

Techniques for reconstructing an object’s microstructure from its diffraction pattern have substantially improved the future imaging potential of next-generation X-ray sources. Yet the same techniques can already be applied to conventional electron microscopes, to extend their resolution to below an ångström.

ARPES measurements of the ‘failed’ superconductor LBCO-1/8 suggest that its pseudogap phase consists of two distinct components. The result could be an important clue into the nature of this phase in the copper oxide superconductors.

The exploration of the Jaynes–Cummings Hamiltonian in a circuit-QED system—where an ‘artificial atom’ made of a superconducting circuit is strongly coupled to a microwave field—provides direct evidence for nonlinearities due to quantum mechanics on the level of single atoms and photons.

An experiment demonstrating the generation of subfemtosecond pulses of light through the interaction of laser light with a solid target underlines the potential of this approach to lead to a new generation of intense sources of attosecond pulses.

Two independent experiments that demonstrate memories for single quantum excitations with storage times on the order of a millisecond—two orders of magnitude longer than reported so far—should help to bring practical long-distance quantum-communication networks a step closer.

Two independent experiments that demonstrate memories for single quantum excitations with storage times of the order of a millisecond—two orders of magnitude longer than reported so far—should help to bring practical long-distance quantum-communication networks a step closer.

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.

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.

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.

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.

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.

Two independent experiments demonstrate that quantum entanglement that has been lost in decoherence processes can be recovered. For the first time such ’entanglement distillation’ has been achieved for states of light that are entangled in continuous variables, which should help to increase the distance over which quantum information can be distributed.

Two independent experiments demonstrate that quantum entanglement that has been lost in decoherence processes can be recovered. For the first time such ‘entanglement distillation’ has been achieved for states of light that are entangled in continuous variables, which should help to increase the distance over which quantum information can be distributed.

Entanglement swapping—a protocol for entangling remote quantum systems without the requirement of direct interaction between them—has been implemented in a completely deterministic fashion, allowing to prepare well-defined entangled states on demand.

Evidence for metal–insulator transitions in dilute 2D electron gases has sparked controversy and debate. A new model suggests such behaviour could arise from strong correlations driven by non-local Coulomb interactions, providing an alternative view to that which considers disorder to be the over-riding influence.

A systematic study of the propagation of ultrasound through a random network of aluminium beads provides the first demonstration of the Anderson localization of classical waves in a 3D system.

Warm dense matter is a complex and little-explored state that is characterized by temperatures usually associated with plasmas but at densities similar to solids. A combination of inelastic X-ray scattering and ab initio simulations enables insight into its structure and behaviour.

The precision of various interferometric measurements can be enhanced by using entangled states of light. Now an experiment demonstrates that all the metrological advantages of the famed Hong–Ou–Mandel quantum interferometer can be realized even with purely classical light.

An experiment that demonstrates efficient absorption of light by a single atom residing in free space should be helpful for designing interfaces for the transfer of quantum information from ‘flying’ qubits to stationary quantum systems, without the need for optical cavities.

A key element in spintronics is the spin-transfer effect, by which the magnetization in a nanomagnet can be switched. The effect has already been demonstrated using spin-polarized electrical currents, but now reversible magnetization switching has been achieved using a pure, chargeless spin current.