Quantum information In physics and computer science, quantum information is information that is held in the state of a quantum system. Quantum information is the basic entity that is studied in the growing field of quantum information theory, and manipulated using the engineering techniques of quantum information processing. Much like classical information can be processed with digital computers, transmitted from place to place, manipulated with algorithms, and analyzed with the mathematics of computer science, so also analogous concepts apply to quantum information. Quantum information Quantum information differs strongly from classical information, epitomized by the bit, in many striking and unfamiliar ways.
Scientists Achieve Quantum Teleportation One of the hurdles to teleportation has been overcome, with the reliable movement of quantum information between two objects separated by a short distance. The achievement is still a very, very long way from the movements familiar from science fiction, but strengthens our confidence in the theory of quantum entanglement, one of the most controversial aspects of modern physics. It may, moreover, assist the much closer goal of quantum computing. Certain subatomic particles always exist in paired states. For example, two electrons may have opposite spins. This is fine initially, but creates a famous paradox if one particle is interfered with in such a way that its spin is changed. Teleportation Teleportation, or Teletransportation, is the theoretical transfer of matter or energy from one point to another without traversing the physical space between them. It is a common subject of science fiction literature, film, and television. Etymology American writer Charles Fort coined the word teleportation in 1931 to describe the strange disappearances and appearances of anomalies, which he suggested may be connected. He joined the Greek prefix tele- (meaning "distant") to the root of the Latin verb portare (meaning "to carry").
Density matrix Explicitly, suppose a quantum system may be found in state with probability p1, or it may be found in state with probability p2, or it may be found in state with probability p3, and so on. The density operator for this system is Quantum tunnelling Quantum tunnelling or tunneling (see spelling differences) refers to the quantum mechanical phenomenon where a particle tunnels through a barrier that it classically could not surmount. This plays an essential role in several physical phenomena, such as the nuclear fusion that occurs in main sequence stars like the Sun. It has important applications to modern devices such as the tunnel diode, quantum computing, and the scanning tunnelling microscope. The effect was predicted in the early 20th century and its acceptance as a general physical phenomenon came mid-century.
IT Conversations Goodbye from IT Conversations Since it’s inception, IT Conversations has published over 3300 audio programs. After ten years of operation and six years with me at the helm, all that is coming to an end. Those of us involved in the day-to-day operation and management of the site have decided that IT Conversations has run its course. We will continue to publish shows until around December 1, 2012.
Physicists add 'quantum Cheshire Cats' to list of quantum paradoxes (Phys.org) —Given all the weird things that can occur in quantum mechanics—from entanglement to superposition to teleportation—not much seems surprising in the quantum world. Nevertheless, a new finding that an object's physical properties can be disembodied from the object itself is not something we're used to seeing on an everyday basis. In a new paper, physicists have theoretically shown that this phenomenon, which they call a quantum Cheshire Cat, is an inherent feature of quantum mechanics and could prove useful for performing precise quantum measurements by removing unwanted properties. The physicists, Yakir Aharonov at Tel Aviv University in Tel Aviv, Israel, and Chapman University in Orange, California, US, and his coauthors have published a paper on quantum Cheshire Cats in a recent issue of the New Journal of Physics. The physicists begin their paper with an excerpt from Lewis Carroll's 1865 novel Alice in Wonderland:
Researchers Succeed in Quantum Teleportation of Light Waves In a real-life use of Schrödinger's theoretical paradoxical cat, researchers report that they were able to quickly transfer a complex set of quantum information while preserving its integrity. The information, in the form of light, was manipulated in such a way that it existed in two states at the same time, and it was destroyed in one spot and recreated in another. The new teleportation breakthrough is a major step toward building safe, effective quantum computers. No felines were harmed in the making of this experiment, which actually studied wave packets of light that existed in a state of quantum superposition, meaning they existed in two different phases simultaneously. This phenomenon is described in Erwin Schrodinger's quantum mechanics thought experiment, in which a cat is simultaneously dead and alive, depending on the state of a subatomic particle.
The Great Beyond Posted on behalf of Declan Butler. The World Health Organization (WHO) announced plans on 24 October to produce millions of doses of two experimental Ebola vaccines by the end of 2015. The Ebola virus has caused about 5,000 deaths in West Africa during the current epidemic. Hundreds of thousands of doses should be available to help affected countries before the end of June, the WHO said at the conclusion of a meeting in Geneva, Switzerland. Vaccine makers, high-level government representatives and regulatory and other bodies gathered to discuss the design and timing of planned clinical trials, as well as issues of supply and funding for mass vaccination programmes. Phase I trials of two vaccine candidates have started, and as many as five other vaccines could begin testing by 2015, says Marie-Paul Kieny, WHO assistant director-general for health systems and innovation.
No-communication theorem In physics, the no-communication theorem is a no-go theorem from quantum information theory, which states that, during measurement of an entangled quantum state, it is not possible for one observer, making a measurement of a subsystem of the total state, to communicate information to another observer. The theorem is important because, in quantum mechanics, quantum entanglement is an effect by which certain widely separated events can be correlated in ways that suggest the possibility of instantaneous communication. The no-communication theorem gives conditions under which such transfer of information between two observers is impossible. These results can be applied to understand the so-called paradoxes in quantum mechanics, such as the EPR paradox, or violations of local realism obtained in tests of Bell's theorem. Informal Overview The theorem is built on the basic presumption that the laws of quantum mechanics hold.
A Lazy Layman's Guide to Quantum Physics That's an easy one: it's the science of things so small that the quantum nature of reality has an effect. Quantum means 'discrete amount' or 'portion'. Max Planck discovered in 1900 that you couldn't get smaller than a certain minimum amount of anything. This minimum amount is now called the Planck unit.
Science / Technology News 2 hrs ago | Seattle Post-Intelligencer Rocket leak delays space station delivery launch With just over an hour remaining, the Space X company called off Monday's planned launch because of a rocket leak. Trending on the Topix Network 2 hrs ago | WTAE-TV Pittsburgh Information theory Overview The main concepts of information theory can be grasped by considering the most widespread means of human communication: language. Two important aspects of a concise language are as follows: First, the most common words (e.g., "a", "the", "I") should be shorter than less common words (e.g., "roundabout", "generation", "mediocre"), so that sentences will not be too long. Such a tradeoff in word length is analogous to data compression and is the essential aspect of source coding.