Latest Quantum measurement Stories

2009-11-18 14:35:59

To exploit the quantum world to the fullest, a key commodity is entanglement"”the spooky, distance-defying link that can form between objects such as atoms even when they are completely shielded from one another. Now, physicists at the Joint Quantum Institute (JQI), a collaborative organization of the National Institute of Standards and Technology (NIST) and the University of Maryland, have developed a promising new source of entangled photons using quantum dots tweaked with a laser....

2009-10-08 09:26:21

Chaotic behavior is the rule, not the exception, in the world we experience through our senses, the world governed by the laws of classical physics. Even tiny, easily overlooked events can completely change the behavior of a complex system, to the point where there is no apparent order to most natural systems we deal with in everyday life. The weather is one familiar case, but other well-studied examples can be found in chemical reactions, population dynamics, neural networks and even the...

2009-07-22 14:10:00

In comparison to classical physics, quantum physics predicts that the properties of a quantum mechanical system depend on the measurement context, i.e. whether or not other system measurements are carried out. A team of physicists from Innsbruck, Austria, led by Christian Roos and Rainer Blatt, have for the first time proven in a comprehensive experiment that it is not possible to explain quantum phenomena in non-contextual terms. The scientists report on their findings in the current issue...

2009-07-15 10:17:34

 In his discussion of accelerated motion on page 60 of The Meaning of Relativity, Albert Einstein made an approximation that allowed him to develop the theory of relativity further. Einstein apparently never had the opportunity to check his original approximation. Now, a University of Missouri physicist has uncovered some clues about the basis of Einstein's theories and presented a more general approximation, which may better link quantum physics with classical physics."Einstein's...

2009-03-05 08:01:08

In quantum mechanics, a vanguard of physics where science often merges into philosophy, much of our understanding is based on conjecture and probabilities, but a group of researchers in Japan has moved one of the fundamental paradoxes in quantum mechanics into the lab for experimentation and observed some of the 'spooky action of quantum mechanics' directly.Hardy's Paradox, the axiom that we cannot make inferences about past events that haven't been directly observed while also acknowledging...

2009-01-15 10:05:42

University of Toronto quantum physicists Jeff Lundeen and Aephraim Steinberg have shown that Hardy's paradox, a proposal that has confounded physicists for over a decade, can be confirmed and ultimately resolved, a task which had seemingly been impossible to perform."For nearly a century, the widespread interpretation of quantum mechanics suggests that everything is uncertain until it is observed, and that observation inevitably alters reality," says Professor Steinberg. "However, in the...

2008-11-26 09:40:00

An $11 million grant from the National Institute of Standards and Technology (NIST) will help the University of California, Berkeley, build a state-of-the-art precision measurement laboratory in the planned new home for the astronomy department and part of the physics department. The award, announced yesterday (Nov. 24), was one of three NIST grants totaling $24 million to build research facilities at universities that will advance technologies and research in line with the mission of the...

2008-08-09 11:47:21

In 2006, Andrew Jordan, professor of physics and astronomy at the University of Rochester, together with Alexander Korotkov at the University of California, Riverside, spelled out how to exploit a quantum quirk to accomplish a feat long thought impossible, and last week a research team at the University of California at Santa Barbara has tested the theory, proving it correct. Quantum particles behave in ways that from our everyday experience seem utterly impossible. For instance, quantum...

2008-04-18 08:10:24

When a tiny, quantum-scale, hypothetical balloon is popped in a vacuum, do the particles inside spread out all over the place as predicted by classical mechanics?The question is deceptively complex, since quantum particles do not look or act like air molecules in a real balloon. Matter at the infinitesimally small quantum scale is both a wave and a particle, and its location cannot be fixed precisely because measurement alters the system.Now, theoretical physicists at the University of...

2008-03-24 14:45:00

The record for the most amount of information sent by a single photon has been broken by researchers at the University of Illinois. Using the direction of "wiggling" and "twisting" of a pair of hyper-entangled photons, they have beaten a fundamental limit on the channel capacity for dense coding with linear optics. "Dense coding is arguably the protocol that launched the field of quantum communication," said Paul Kwiat, a John Bardeen Professor of Physics and Electrical and Computer...

Word of the Day
  • A Roman unit of weight, 1⁄1728 of a pound.
  • A weight of four grains used in weighing gold and precious stones; a carat.
  • In anatomy, a formation suggesting a husk or pod.
  • The lowest unit in the Roman coinage, the twenty-fourth part of a solidus.
  • A coin of base silver of the Gothic and Lombard kings of Italy.
'Siliqua' comes from a Latin word meaning 'a pod.'