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'Dead time' limits quantum cryptography speeds

09-28-2007 · EurekAlert!

According to a new paper by researchers at NIST and the Joint Quantum Institute, technological and security issues will stall maximum transmission rates at levels comparable to that of a single broadband connection, such as a cable modem, unless researchers reduce 'dead times' in the detectors that receive quantum-encrypted messages.

Keywords: dead, time, limits, quantum, cryptography, speeds, limit, speed

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Matter flashed at ultra speed
06-12-2007 · EurekAlert!
Using a robotic telescope at the ESO La Silla Observatory, astronomers have for the first time measured the velocity of the explosions known as gamma-ray bursts. The material is travelling at the extraordinary speed of more than 99.999 percent of the velocity of light, the maximum speed limit in the universe.
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Restoring sight, advances in fertility treatments and better visibility for pilots at FIO
08-23-2007 · EurekAlert!
Frontiers in Optics 2007, the 91st Annual Meeting of the Optical Society of America, will be held from Sept. 16-20 in San Jose, Calif. Following are a few of the many technical highlights to be discussed at the meeting: •Restoring Sight, One Pixel at a Time•Near-Infrared LIDAR Helps Pilots•Better, Stronger, Faster: High-Throughput Sperm Sorting •Detecting Malaria with Light•Gigantic Photoresponse Can Speed Up Optical Switches for Faster Internet Speeds •Explaining a 21st Century Version of Young's Experiment
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MIT: Turning 'funky' quantum mysteries into computing reality
02-16-2008 · EurekAlert!
The strange world of quantum mechanics can provide a way to surpass limits in speed, efficiency and accuracy of computing, communications and measurement, according to research by MIT scientist Seth Lloyd.
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Physicists pin down spin of surface atoms
09-12-2007 · EurekAlert!
UC-Berkeley physicists have successfully measured the atomic spin of an isolated atom, one of the necessary steps on the road to quantum computers and spintronics devices. Using a scanning tunneling microscope with a spin-polarized tip, Michael Crommie and colleagues mapped the surface topography and the surface energy levels to determine the spin of adatoms, the first time this has been measured directly.
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First teleportation between light and matter
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Physicists have for the first time transmitted quantum states between atoms and light.
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Physicists reveal water's secrets in journal 'Science'
03-02-2007 · EurekAlert!
Equipped with high-speed computers and the laws of physics, scientists from the University of Delaware and Radboud University in the Netherlands have developed a new method to "flush out" the hidden properties of water. The research is reported in Science. Their first-principle simulation of water molecules -- based exclusively on quantum physics laws -- has numerous applications, from biological investigations of protein folding and other life processes, to the design of the next generation of power plants.
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Advance in understanding of blood pressure gene could lead to new treatments
02-04-2007 · EurekAlert!
Research by scientists at UCL (University College London) has clearly demonstrated for the first time the structure and function of a gene crucial to the regulation of blood pressure. The discovery could be important in the search for new treatments for illnesses such as heart disease, the UK's biggest killer. In a paper published online today in Nature Medicine, the team, led by Professor Patrick Vallance and Dr James Leiper, UCL Department of Medicine, reveal the role of the human gene dimethylarginine dimethylaminohydrolase (DDAH), showing that loss of DDAH activity disrupts nitric oxide (NO) production. NO is critical in the regulation of blood pressure, nervous system functions and the immune system. The role of DDAH is to break down modified amino acids (Asymmetric dimethylarginine (ADMA) and monomethyl arginine (L-NMMA)) that are produced by the body and have been shown to inhibit NO synthase. These molecules accumulate in various disease states including diabetes, renal failure and pulmonary and systemic hypertension, and their concentration in plasma (the fluid component of blood) is strongly predicative of cardiovascular disease and death. In a healthy human body, the majority of ADMA is eliminated through active metabolism by DDAH. Scientists have hypothesised that if DDAH function is impaired, NO production is reduced, and that this could be an important feature of increased cardiovascular risk. To examine this pathway in more detail, the researchers deleted the DDAH gene in mice. These mice went on to develop hypertension, or high blood pressure. They also designed specific inhibitors (small molecules) which bind to the active site of human DDAH. These small molecule inhibitors also induced hypertension in mice, confirming the importance of DDAH in the regulation of blood pressure. Dr Leiper, UCL Medicine, said: “These genetic and chemical approaches to disrupt DDAH showed remarkably consistent results, and provide compelling evidence that loss of DDAH function increases the concentration of ADMA and thereby disrupts vascular NO signalling. “There has been considerable scientific interest in this pathway and the role of ADMA as a novel risk factor, but so far there's been little evidence to support the idea that it's a cause of disease, rather than just a marker. Genes and their pathways are crucial to our understanding of cardiovascular disease and a better understanding of DDAH-1 could lead to important new treatments. “It could help us to establish if genetic variation predisposes certain people to these diseases, or whether environmental factors exert some of their effects through modulation of DDAH activity. “Our research also shows that this pathway could be harnessed therapeutically to limit production of NO in certain situations where too much nitric oxide is a bad thing; for example, hypotension and septic shock. These are some of the biggest problems in intensive care medicine and there is a huge unmet need for drug treatments.” The study, which was carried out at UCL's Rayne Institute, was funded by grants from the British Heart Foundation, the Wellcome Trust and the Medical Research Council. Professor Jeremy Pearson, Associate Medical Director of the British Heart Foundation, said: "The unexpected finding in the 1980s that a simple gas, nitric oxide (NO), is made by cells in the blood vessel wall and is a powerful control of blood vessel relaxation led to the award of the Nobel Prize in 1998 to its discoverers. "More recently, there has been increasing evidence that impairment of NO production is likely to be an important factor in the development of heart and circulatory disease, but the mechanisms responsible are not fully understood. "This study suggests for the first time that the loss of the activity of the enzyme DDAH-1 leads to reduced NO production and may cause heart and circulatory disease. These findings are likely to be important in the search for new ways to optimise the health of our blood vessels." ### Notes for Editors 1. For more information, please contact Ruth Metcalfe in the UCL Media Relations Office on tel: +44 (0)20 7679 9739, mobile: +44 (0)7990 675 947, out of hours: +44 (0)7917 271 364, e-mail: r.metcalfe@ucl.ac.uk2. 'Disruption of methylarginine metabolism impairs vascular homeostasis' is published in the February issue of the journal Nature Medicine. Advance online publication is embargoed to 18.00 GMT (13.00 US Eastern) Sunday 4 February 2007. Journalists can obtain copies of the paper by contacting the UCL Media Relations Office.3. The study was funded by the British Heart Foundation, the Wellcome Trust and the Medical Research Council. About UCL Founded in 1826, UCL was the first English university established after Oxford and Cambridge, the first to admit students regardless of race, class, religion or gender, and the first to provide systematic teaching of law, architecture and medicine. In the government's most recent Research Assessment Exercise, 59 UCL departments achieved top ratings of 5* and 5, indicating research quality of international excellence. UCL is the fourth-ranked UK university in the 2006 league table of the top 500 world universities produced by the Shanghai Jiao Tong University. UCL alumni include Mahatma Gandhi (Laws 1889, Indian political and spiritual leader); Jonathan Dimbleby (Philosophy 1969, writer and television presenter); Junichiro Koizumi (Economics 1969, Prime Minister of Japan); Lord Woolf (Laws 1954, Lord Chief Justice of England & Wales); Alexander Graham Bell (Phonetics 1860s, inventor of the telephone), and members of the band Coldplay.
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IBM and Imago find a crucial difficulty in semiconductor device scaling
09-06-2007 · EurekAlert!
As reported in the Sept. 7, 2007 issue of Science, IBM and Imago used atom probe tomography to observe, for the first time, distributions of individual dopant atoms at defects in semiconductor devices. The researchers found that clusters of dopant atoms form around defects after ion implantation and annealing. These clusters persist even after considerable thermal treatment, creating dopant fluctuations that may ultimately limit the scalability of semiconductor devices.
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'Tornadoes' are transferred from light to sodium atoms
11-09-2006 · EurekAlert!
For the first time, tornado-like rotational motions have been transferred from light to atoms in a controlled way at NIST. The new quantum physics technique can be used to manipulate Bose-Einstein condensates, a state of matter of worldwide research interest and possibly used in quantum information systems.
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Physicists reveal water's secrets in journal Science
03-02-2007 · EurekAlert!
Equipped with high-speed computers and the laws of physics, scientists from the University of Delaware and Radboud University in the Netherlands have developed a new method to "flush out" the hidden properties of water. The research is reported in Science. Their first-principle simulation of water molecules -- based exclusively on quantum physics laws -- has numerous applications, from biological investigations of protein folding and other life processes, to the design of the next generation of power plants.
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