News & Views in 2005

For a 'real life' quantum computer, mere capability is not good enough. It also has to defy disturbances attempting to weaken its special powers. To succeed, the task has to be addressed on various levels.

Repetition is probably the simplest method of error control. If an experiment fails, repeat it, and do so until it eventually succeeds. Quantum mechanics gives leeway for alternative approaches.

A tighter limit on the half-life of a tellurium nucleus for 'neutrinoless double-beta decay' marks progress towards a better understanding of the ever-elusive neutrinos and the measurement of their mass.

The emergence of both complex and repeating patterns in a simple microfluidic circuit provides an ideal test-bed for studying self-organized complexity, without the need for exhaustive dynamic control over the parameters that influence complex behaviour.

Computer viruses can spread through networks with alarming speed. But there is hope that those fighting the plague can keep up with the pace.

Berry phases and hidden chiralities are thought to be behind some of the most exotic states in quantum magnets. Polarized neutron scattering unveils the influence of such behaviour on the dynamics of quantum systems.

A planet's rings can be distorted by the gravitational pull of its satellites, and these complex interactions have been difficult to disentangle. Saturn's moon Prometheus, however, has now been caught returning to the scene of the crime.

The spin of a photoluminescent nitrogen centre in diamond has a long life-time that could be useful as a qubit, for example. It's difficult enough to image such a single spin — imagine using that bright spin to detect nearby invisible 'dark' spins.

An atomic Bose–Einstein condensate represents a highly correlated, coherent state of matter. Experiments now reveal that the collective matter-wave properties extend to include coherent dynamics of the spin degrees of freedom.

Excited quantum states in nature are normally extremely short-lived, and this certainly applies to most nuclei. But what makes the metastable nuclear states different? And how can we exploit them for useful applications?

Whether or not a superconductor is truly superconducting depends on its size and even its shape. In a geometry intermediate between one and two dimensions, it seems a thin film does not reach a state of zero resistance except at zero temperature.

Read-heads based on the manipulation of spin have already revolutionized the performance of magnetic data storage devices. The development of more-complex spin-devices using carbon nanotubes could enable the next logical step in spintronics.

The discovery of a superconductor is always exciting, but particularly so when the material is a common stationery item and the superconductivity is possibly unconventional.

Although recent years have seen substantial improvements in the perfomance of photonic-crystal cavities, their design has been a rather hit and miss affair. By turning around the general approach to cavity design through the use of Bloch waves, an important avenue to the discovery of optimal cavity geometries could be opened.

Physical phenomena associated with a quantum critical point are different from their classical counterpart in many ways. For one thing, the effects of quantum criticality might in some cases be observed far away, at unexpectedly high temperatures.

The wave nature of matter is well established for isolated particles, from electrons to molecules. Now experiment reveals that even deeply buried core-shell electrons in a diatomic molecule can emit coherently.

There is good reason to suppose that the Universe has more than three spatial dimensions. The first dedicated search for warped extra dimensions has drawn a blank, but hopes are high for the future.

Crackling noise emitted in systems as diverse as candy wrappers and earthquakes show strikingly similar behaviour, but how it is influenced by the details of these systems is unclear. A study that identifies the microscopic origin of unexplained asymmetries in the noise emitted by a magnet could provide some answers.

Wet sand is more stable than dry sand, but exactly how this greater stability arises has been the subject of considerable discussion. Conflicting ideas are now unified by a hybrid theory that considers both surface and bulk properties of a sandpile.