News Picks home

August 20, 2008

Quantum physics gets spooky

ScienceNOW: This might be a rare case about which Einstein was wrong. More than 60 years ago, the great physicist scoffed at the idea that anything could travel faster than light, even though quantum mechanics had suggested such a condition. Now four Swiss researchers have brought the possibility closer to reality. Testing a concept called "spooky action at a distance"--a phrase used by Einstein in criticizing the phenomenon--they have shown that two subatomic particles can communicate nearly instantaneously, even if they are separated by cosmic distances.

August 15, 2008

The strength of the casimir force in a vacuum

Nature: A vacuum may be devoid of matter, but its shape is still important. The strength of the Casimir force caused by quantum fluctuations in the space between surfaces is critically dependent on their nanometre-scale shape.

July 31, 2008

Let quantum mechanics improve your images

Science: Images are superb conveyors of information. Recent research has shown how subtle quantum mechanical aspects of light can profoundly influence the nature of image formation.In the July 25 issue of Science, two important advances in this emerging area of quantum imaging are presented. Wagner et al. report on the behavior of two beams of light that are quantum mechanically entangled in position and direction of propagation--that is, the outcome of measurements on one beam depends on what sort of measurements have been performed on the other beam. Boyer et al. show that two image-bearing light beams can be entangled such that strong quantum correlations exist both between the two beams and between individual image features within each beam. They find two sorts of quantum correlations: The intensities of the two beams fluctuate in unison, at a level not permitted by classical statistics, and the noise in one part of the light field can be reduced, or "squeezed," at the expense of another part.

July 23, 2008

Quantum physics makes water different

Science News: The length of bonds connecting water molecules could demonstrate quantum effects and help explain some of water’s weirdness.

June 26, 2008

Quantum coherence and entanglement with ultracold atoms in optical lattices

Nature: At nanokelvin temperatures, ultracold quantum gases can be stored in optical lattices, which are arrays of microscopic trapping potentials formed by laser light. Such large arrays of atoms provide opportunities for investigating quantum coherence and generating large-scale entanglement, ultimately leading to quantum information processing in these artificial crystal structures. These arrays can also function as versatile model systems for the study of strongly interacting many-body systems on a lattice.

June 23, 2008

Quantifying entanglement in macroscopic systems

Nature: Traditionally, entanglement was considered to be a quirk of microscopic objects that defied a common-sense explanation. Now, however, entanglement is recognized to be ubiquitous and robust. With the realization that entanglement can occur in macroscopic systems — and with the development of experiments aimed at exploiting this fact — new tools are required to define and quantify entanglement beyond the original microscopic framework.

June 19, 2008

Quantum weirdness and surrealism

Nature: A joint exploration of early modern physics and the surreal art movement shows these twentieth-century revolutions had more in common than we thought, explains Nature's Philip Ball.

May 23, 2008

Can information get back out of black holes?

Nature News: If you were sucked into a black hole, you wouldn't stand a chance. But new calculations suggest that some things might survive travelling to the heart of the Universe's darkest objects.

'Quantum information' could make it through a black hole, says a group of theorists at Pennsylvania State University. If their calculation holds water, it would solve an important problem for quantum mechanics — and make the behaviour of black holes easier to predict.

COMPANY SPOTLIGHT