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Quantum Entanglement Could Stretch Across Time

Quantum Entanglement Could Stretch Across Time
In the weird world of quantum physics, two linked particles can share a single fate, even when they’re miles apart. Now, two physicists have mathematically described how this spooky effect, called entanglement, could also bind particles across time. If their proposal can be tested, it could help process information in quantum computers and test physicists’ basic understanding of the universe. “You can send your quantum state into the future without traversing the middle time,” said quantum physicist S. Jay Olson of Australia’s University of Queensland, lead author of the new study. In ordinary entanglement, two particles (usually electrons or photons) are so intimately bound that they share one quantum state — spin, momentum and a host of other variables — between them. Physicists have figured out how to use entanglement to encrypt messages in uncrackable codes and build ultrafast computers. Olson explained them with a Star Trek analogy. “It stimulated our imaginations,” said Fuentes. Related:  Quantumly

10/23/13, 16:19-- This may solve Einstein's A Step Towards Quantum Computing: Entangling 10 Billion Particles | 80beats In life, most people try to avoid entanglement, be it with unsavory characters or alarmingly large balls of twine. In the quantum world, entanglement is a necessary step for the super-fast quantum computers of the future. According to a study published by Nature today, physicists have successfully entangled 10 billion quantum bits, otherwise known qubits. But the most significant part of the research is where the entanglement happened–in silicon–because, given that most of modern-day computing is forged in the smithy of silicon technology, this means that researchers may have an easier time incorporating quantum computers into our current gadgets. Quantum entanglement occurs when the quantum state of one particle is linked to the quantum state of another particle, so that you can’t measure one particle without also influencing the other. Spinning particles are all well and nice, but what do they have to do with computing? Image: Stephanie Simmons

10/23/13, 19:15-- This actually coincides with Quantum Entanglement Whatever happened to one particle would thus immediately affect the other particle, wherever in the universe it may be. Einstein called this "Spooky action at a distance." Amir D. Aczel, Entanglement, The Greatest Mystery In Physics. The Theory When a photon (usually polarized laser light) passes through matter, it will be absorbed by an electron. When the original photon splits into two photons, the resulting photon pair is considered entangled. The process of using certain crystals to split incoming photons into pairs of photons is called parametric down-conversion. Normally the photons exit the crystal such that one is aligned in a horizontally polarized light cone, the other aligned vertically. To illustrate, if an entangled photon meets a vertical polarizing filter (analagous to the fence in Figure 4.4), the photon may or may not pass through. The Practice Experiments have shown that Einstein may have been wrong: entangled photons seem to communicate instantaneously. Figure 5.1.

10/23/13, 19:19-- This essentially would be Bibliography of Quantum Cryptography by Gilles Brassard Département IRO, Université de Montréal. The original PostScript file from Gilles Brassard - provided by Edith Stoeveken - was converted to ASCII and reformatted in HTML; Sept 2 1994, Stephan Kaufmann. Abstract This paper provides an extensive annotated bibliography of papers that have been written on quantum cryptography and related topics. 1. For ages, mathematicians have searched for a system that would allow two people to exchange messages in perfect privacy. In addition to key distribution, quantum techniques may also assist in the achievement of subtler cryptographic goals, important in the post-cold war world, such as protecting private information while it is being used to reach public decisions. In the past few years, a remarkable surge of interest in the international scientific and industrial community has propelled quantum cryptography into mainstream computer science and physics. 2. Quantum cryptography is best known for key distribution. 3. 4. 5. 6. 7.

Squeeze light to teleport quantum energy - physics-math - 23 January 2014 Putting the squeeze on light may be the key to teleporting energy across vast distances. Although the amount of energy that could theoretically be transmitted is tiny for now, it could be enough to power quantum computers that don't overheat. For years physicists have been smashing distance records for quantum teleportation, which exploits quantum entanglement to send encrypted information. No physical matter is transmitted, and nothing is travelling faster than light. Physicists have done this with light and with matter, such as entangled ions. Quantum toothpaste Theory has it that a vacuum is not truly empty – it is constantly roiling with tiny fluctuations that cause particles to pop in and out of existence. The quantum field in the vacuum of space is usually at its lowest energy level. Light work To get greater reach, Hotta and his colleagues have now applied a twist to their theory that adds squeezed light to the vacuum. Normally, photons travelling through a vacuum arrive randomly.

How Quantum Cryptology Works" The idea that a vote cast by a person remains the same after he submitted it is taken very seriously in any democracy. Voting is the right of the citizen, and it's how we choose the people who make important decisions on our behalf. When the security of the ballot is compromised, so, too, is the individual's right to choose his leaders. There are plentiful examples of vote tampering throughout history in the United States and in other countries. ­But, hopefully, the days when paper ballots get lost on the back roads of Florida en route to be counted will soon be gone, and the hanging chad will become an obscure joke on sitcom reruns from the early 21st century. One of the ways to safeguard votes is to limit access to them when they're being transferred from precincts to central polling stations where they're tallied. Id Quantiques' quantum encryption is the first public use of such a technique.

Traditional Cryptology Problems" Both the secret-key and public-key methods of cryptology have unique flaws. Oddly enough, quantum physics can be used to either solve or expand these flaws. The problem with public-key cryptology is that it's based on the staggering size of the numbers created by the combination of the key and the algorithm used to encode the message. These numbers can reach unbelievable proportions. What's more, they can be made so that in order to understand each bit of output data, you have to also understand every other bit as well. The keys used in modern cryptography are so large, in fact, that a billion computers working in conjunction with each processing a billion calculations per second would still take a trillion years to definitively crack a key [source: Dartmouth College]. But SKC has its problems as well. It's possible to send a message concerning which key a user would like to use, but shouldn't that message be encoded, too? Quantum physics has provided a way around this problem.

An important quantum algorithm may actually be a property of nature Back in 1996, a quantum physicist at Bell Labs in New Jersey published a new recipe for searching through a database of N entries. Computer scientists have long known that this process takes around N steps because in the worst case, the last item on the list could be the one of interest. However, this physicist, Lov Grover, showed how the strange rules of quantum mechanics allowed the search to be done in a number of steps equal to the square root of N. That was a big deal. Searching databases is a foundational task in computer science, used for everything from finding telephone numbers to breaking cryptographic codes. So any speed-up is a significant advance. Quantum mechanics provided an additional twist. But despite the interest, implementing Grover’s algorithm has taken time because of the significant technical challenges involved. Today Stéphane Guillet and colleagues at the University of Toulon in France say this may be easier than anybody expected. First some background.

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