http://www.physorg.com/physics-news/quantum-physics/ en-us PhysOrg.com provides the latest news on quantum physics, wave particle duality, quantum theory, quantum mechanics, quantum entanglement, quantum teleportation, and quantum computing. Quantum computing promises ultra-fast communication, computation and more powerful ways to encrypt sensitive information. But trying to use quantum states as carriers of information is an extremely delicate business. Now two physicists have shown, mathematically, how to gently tease out unwanted knots in quantum communication, while keeping the information intact. Their work is reported in the current issue of Physical Review Letters and highlighted with a Viewpoint in Physics. http://www.physorg.com/news178211021.html Physics - Quantum Physics Mon, 23 Nov 2009 15:20:01 EST news178211021 Physicists at UC Santa Barbara have made an important advance in electrically controlling quantum states of electrons, a step that could help in the development of quantum computing. The work is published online today on the Science Express Web site. http://www.physorg.com/news177938057.html Physics - Quantum Physics Fri, 20 Nov 2009 11:18:55 EST news177938057 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 and the University of Maryland, have developed a promising new source of entangled photons using quantum dots tweaked with a laser. The JQI technique may someday enable more compact and convenient sources of entangled photon pairs than presently available for quantum information applications such as the distribution of "quantum keys" for encrypting sensitive messages. http://www.physorg.com/news177763808.html Physics - Quantum Physics Wed, 18 Nov 2009 10:50:39 EST news177763808 Physicists at the National Institute of Standards and Technology have demonstrated the first "universal" programmable quantum informationprocessor able to run any program allowed by quantum mechanics -- the rules governing the submicroscopic world -- using two quantum bits (qubits) of information. The processor could be a module in a future quantum computer, which theoretically could solve some important problems that are intractable today. http://www.physorg.com/news177515046.html Physics - Quantum Physics Sun, 15 Nov 2009 13:45:25 EST news177515046 (PhysOrg.com) -- In a recently published paper, Aram Harrow at the University of Bristol and colleagues from MIT in the United States have discovered a quantum algorithm that solves large problems much faster than conventional computers can. http://www.physorg.com/news177011105.html Physics - Quantum Physics Mon, 09 Nov 2009 18:20:02 EST news177011105 In an international first, scientists from the Institute of Quantum Optics and Quantum Information (IQOQI, Austria) produced a Bose-Einstein condensate of the alkaline-earth element strontium, thus narrowly winning an international competition between many first-rate scientific groups. Choosing the isotope 84Sr, which has received little attention so far, proved to be the right choice for the breakthrough. It can now be regarded as an ideal candidate for future experiments with atomic two-electron systems. http://www.physorg.com/news176994672.html Physics - Quantum Physics Mon, 09 Nov 2009 13:11:51 EST news176994672 (PhysOrg.com) -- Physicists at Harvard University have created a quantum gas microscope that can be used to observe single atoms at temperatures so low the particles follow the rules of quantum mechanics, behaving in bizarre ways. http://www.physorg.com/news176569616.html Physics - Quantum Physics Wed, 04 Nov 2009 15:07:42 EST news176569616 (PhysOrg.com) -- Many scientists believe that quantum entanglement is required in order for effective quantum computing. Entanglement takes place when there is a connection that exists between two objects - even when they are spatially separated - that allows what happens to one to happen to the other. The link is such that each entangled object cannot be adequately described without its counterpart. So far, entangling qubits for practical use has been difficult, since scientists want to be able to entangle several qubits at once. http://www.physorg.com/news176364815.html Physics - Quantum Physics Mon, 02 Nov 2009 11:20:01 EST news176364815 (PhysOrg.com) -- For more than 50 years, physicists have been intrigued by the concept of closed time-like curves (CTCs). Because a CTC returns to its starting point, it raises the possibility of traveling backward in time. More recently, physicists have theorized that CTC-assisted computers could enable ideal quantum state discrimination, and even make classical computers (with CTCs) equally as powerful as quantum computers. However, a new study argues that CTCs, if they exist, might actually provide much less computational benefit than previously thought. http://www.physorg.com/news175421039.html Physics - Quantum Physics Thu, 22 Oct 2009 10:40:01 EST news175421039 In the quest for smaller, faster computer chips, researchers are increasingly turning to quantum mechanics -- the exotic physics of the small. The problem: the manufacturing techniques required to make quantum devices have been equally exotic. That is, until now. http://www.physorg.com/news174833014.html Physics - Quantum Physics Thu, 15 Oct 2009 13:44:35 EST news174833014 (PhysOrg.com) -- (PhysOrg.com) -- A team of scientists from the Max Planck Institute of Quantum Optics and the Ludwig Maximilians University have succeeded in applying a novel optical method to nano-mechanical oscillators. New fabrication techniques have enabled the development of on-chip mechanical elements whose dimensions are on the nanometer scale. Their application, however, has been limited by the lack of sufficiently sensitive techniques for measuring the motion of these tiny devices. http://www.physorg.com/news174757411.html Physics - Quantum Physics Wed, 14 Oct 2009 16:50:59 EST news174757411 (PhysOrg.com) -- What if atoms could be used to perform the functions currently the province of electronic devices? The goal of atomtronics is to do just that by creating analogues to the common items found in electronic devices. Ron Pepino, a graduate student at JILA and the University of Colorado, believes that he and his colleagues have found a way to create the atomtronic versions of diode and transistor circuits. The work of Pepino, Cooper, Anderson and Holland is described in Physical Review Letters: "Atomtronic Circuits of Diodes and Transistors." http://www.physorg.com/news174303837.html Physics - Quantum Physics Fri, 09 Oct 2009 10:44:44 EST news174303837 (PhysOrg.com) -- In recent years, quantum computers have lost some of their luster. In the 1990s, it seemed that they might be able to solve a class of difficult but common problems - the so-called NP-complete problems - exponentially faster than classical computers. Now, it seems that they probably can't. In fact, until this week, the only common calculation where quantum computation promised exponential gains was the factoring of large numbers, which isn't that useful outside cryptography. http://www.physorg.com/news174286879.html Physics - Quantum Physics Fri, 09 Oct 2009 06:01:53 EST news174286879 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. http://www.physorg.com/news174143570.html Physics - Quantum Physics Wed, 07 Oct 2009 14:13:42 EST news174143570 (PhysOrg.com) -- For the first time, physicists have demonstrated the quantum entanglement of three light beams, all of different wavelengths. Entanglement of two light beams of different wavelengths has already been demonstrated, but the researchers explain that going beyond two beams is important since three beams can serve as connections at the nodes of a quantum network. http://www.physorg.com/news174133022.html Physics - Quantum Physics Wed, 07 Oct 2009 11:17:35 EST news174133022 (PhysOrg.com) -- For the first time, physicists have experimentally demonstrated a four-qubit bound-entangled state - a peculiar form of entanglement that cannot be distilled (optimized) by the usual means. However, the scientists have found a novel method for distilling the entanglement by working with two qubits at a time. As the researchers explain, the special properties of bound entanglement could make it a useful quantum resource for new multiparty communication and secret sharing schemes, and the results could also contribute to a deeper understanding of the foundations of quantum mechanics. http://www.physorg.com/news173517599.html Physics - Quantum Physics Wed, 30 Sep 2009 10:00:01 EST news173517599 (PhysOrg.com) -- By greatly amplifying one photon from an entangled photon pair, physicists have theoretically shown that human eyes can be used as detectors to observe quantum effects. Usually, detecting quantum phenomena requires sensitive photon detectors or similar technology, keeping the quantum world far removed from our everyday experience. By showing that it`s possible to perform quantum optics experiments with human eyes as detectors, the physicists can bring quantum phenomena closer to the macroscopic level and to everyday life. http://www.physorg.com/news173423784.html Physics - Quantum Physics Tue, 29 Sep 2009 09:10:03 EST news173423784 (Santa Barbara, Calif.) -- Physicists at UC Santa Barbara have made an important advance in quantum mechanics using a superconducting electrical circuit. The finding is reported in this week's issue of the journal Nature. http://www.physorg.com/news172936800.html Physics - Quantum Physics Wed, 23 Sep 2009 15:00:50 EST news172936800 (PhysOrg.com) -- There's nothing University of Nebraska-Lincoln physicist Herman Batelaan likes more than a challenge. And there are few areas of science more challenging than working at the sub-atomic, or quantum, world, where the laws of physics are different from those of our macro world. http://www.physorg.com/news172919873.html Physics - Quantum Physics Wed, 23 Sep 2009 10:18:51 EST news172919873 (PhysOrg.com) -- Diamonds, it has long been said, are a girl's best friend. But a research team including a physicist from the National Institute of Standards and Technology has recently found that the gems might turn out to be a patient's best friend as well. http://www.physorg.com/news172862154.html Physics - Quantum Physics Tue, 22 Sep 2009 18:16:51 EST news172862154 (PhysOrg.com) -- While researchers have already demonstrated the building blocks for few-bit quantum computers, scaling these systems up to large quantum computers remains a challenge. One of the biggest problems is developing physical systems that can reliably store thousands of qubits, and enabling bits and pairs to be addressed individually for gate operations. http://www.physorg.com/news171705608.html Physics - Quantum Physics Wed, 09 Sep 2009 09:02:02 EST news171705608 (PhysOrg.com) -- A primitive quantum computer that uses single particles of light (photons) whizzing through a silicon chip has performed its first mathematical calculation. This is the first time a calculation has been performed on a photonic chip and it is major step forward in the quest to realise a super-powerful quantum computer. http://www.physorg.com/news171213314.html Physics - Quantum Physics Thu, 03 Sep 2009 16:15:49 EST news171213314 Does an exciting but controversial new model of quantum gravity reproduce Einstein's theory of general relativity? Scientists at Texas A&M University in the US explore this question in a paper appearing in Physical Review Letters and highlighted with a Viewpoint in the August 24th issue of Physics. http://www.physorg.com/news170333445.html Physics - Quantum Physics Mon, 24 Aug 2009 12:20:01 EST news170333445 (PhysOrg.com) -- Transitions are exciting. And at temperatures close to absolute zero, studying the transition from one quantum phase to another tantalizes physicists looking for a deeper understanding of the fundamental laws of the universe. http://www.physorg.com/news170006749.html Physics - Quantum Physics Thu, 20 Aug 2009 17:07:24 EST news170006749 Quantum mechanics and Einstein's theory of general relativity are both extremely accurate theories of how the universe works, but all attempts to combine the two into a unified theory have ended in failure. When physicists try to calculate the properties of a quantum theory of gravity, they find quantities that become infinite -- infinities that are so bad they can't be removed by mathematical gambits that work in other areas of physics. http://www.physorg.com/news169733869.html Physics - Quantum Physics Mon, 17 Aug 2009 13:18:47 EST news169733869 (PhysOrg.com) -- Since the early days of quantum mechanics, scientists have been trying to understand the many strange implications of the theory: superpositions, wave-particle duality, and the observer`s role in measurements, to name a few. Now, a new proposed law of physics that describes the geometry of physical reality on the cosmological scale might help answer some of these questions. Plus, the new law could give some clues about the role of gravity in quantum physics, possibly pointing the way to a unified theory of physics. http://www.physorg.com/news169725980.html Physics - Quantum Physics Mon, 17 Aug 2009 11:07:00 EST news169725980 Scientists at UC Santa Barbara have devised a new type of superconducting circuit that behaves quantum mechanically -- but has up to five levels of energy instead of the usual two. The findings are published in the August 7 issue of Science. http://www.physorg.com/news169221847.html Physics - Quantum Physics Tue, 11 Aug 2009 15:04:34 EST news169221847 Raising prospects for building a practical quantum computer, physicists at the National Institute of Standards and Technology have demonstrated sustained, reliable information processing operations on electrically charged atoms (ions). The new work, described in the August 6 issue of Science Express, overcomes significant hurdles in scaling up ion-trapping technology from small demonstrations to larger quantum processors. http://www.physorg.com/news168791155.html Physics - Quantum Physics Thu, 06 Aug 2009 15:26:23 EST news168791155 (PhysOrg.com) -- Physicists from The University of Queensland have found the emerging field of quantum computing may be more stable than previously thought. http://www.physorg.com/news168706585.html Physics - Quantum Physics Wed, 05 Aug 2009 16:50:01 EST news168706585 (PhysOrg.com) -- 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 of Nature. http://www.physorg.com/news167461123.html Physics - Quantum Physics Wed, 22 Jul 2009 13:00:04 EST news167461123