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	Quantum Zeno effect - Wikipedia, the free encyclopedia
		The quantum Zeno effect is a quantum mechanical phenomenon first described by George Sudarshan and Baidyanaith Misra of the University of Texas in 1977.
		In general, the Zeno effect can be deﬁned as class of phenomena when a transition is suppressed by some interaction which allows the interpretation of the ﬁnal state in terms of "a transition has not yet occured" or "a transition already occurred" ([1]).
		So in the decoherence picture, the quantum Zeno effect corresponds to the limit where a quantum system is continuously coupled to the environment, and where that coupling is infinitely strong, and where the "environment" is an infinitely large source of thermal randomness.
	en.wikipedia.org /wiki/Quantum_Zeno_effect (547 words)

	Zeno's paradoxes - Wikipedia, the free encyclopedia
		Zeno's paradoxes are a set of paradoxes devised by Zeno of Elea to support Parmenides' doctrine that "all is one" and that contrary to the evidence of our senses, the belief in plurality and change is mistaken, and in particular that motion is nothing but an illusion.
		Zeno's arguments are perhaps the first examples of a method of proof called reductio ad absurdum also known as proof by contradiction.
		This effect is usually called the quantum Zeno effect as it is strongly reminiscent of Zeno's arrow paradox.
	en.wikipedia.org /wiki/Zenos_paradoxes (3642 words)

	Zeno - Wikipedia, the free encyclopedia
		Zeno (emperor) (c.425–491), Emperor of the Eastern Roman Empire 474–491
		Zeno of Citium (333–264 BC), Hellenistic philosopher of the Painted Porch, founder of Stoicism
		Quantum Zeno effect, an effect in quantum mechanics which disallows certain conditions in the decaying of a quantum state
	en.wikipedia.org /wiki/Zeno (232 words)

	Quantum Zeno effect: Facts and details from Encyclopedia Topic (Site not responding. Last check: 2007-10-13)
		Quantum mechanics is a fundamental physical theory which extends and corrects newtonian mechanics, especially at the atomic and subatomic levels....
		In certain interpretations of quantum mechanics, wavefunction collapse is one of two processes by which quantum systems apparently evolve according to the laws...
		In quantum mechanics, quantum decoherence is the general term for the consequences of irreversible quantum entanglement....
	www.absoluteastronomy.com /encyclopedia/q/qu/quantum_zeno_effect.htm (1115 words)

	[No title]
		The QZE appears as a result of spontaneous emission and the corresponding collapse of the wavefunction.
		In this paper we investigate the role of the quantum Zeno effect by means of Monte-Carlo wavefunction (MCWF) simulations of the three-level V scheme.
		The quantum Zeno effect is the suppression of coherent transitions between quantum states due to frequent measurements [12-13] and has been observed experimentally in a V scheme [13].
	www.science.uva.nl /research/aplp/lwi/qzeno.htm (498 words)

	Quantum Seeing in the Dark
		According to the rules of quantum mechanics, interference Occurs whenever there is more than one possible way for a given outcome to happen, and the ways are not distinguishable by any means (this is a more general definition of interference than is often given in textbooks).
		The phenomenon is called the quantum Zeno effect, because it resembles the famous paradox raised by the Greek philosopher Zeno, who denied the possibility of motion to an arrow in flight because it appears "frozen" at each instant of its flight.
		The quantum feline is prepared so that it exists in two states at once: it is both alive and dead at the same time-a superposition of two states.
	www.fortunecity.com /emachines/e11/86/seedark.html (4841 words)

	Proceedings of the 6th Central-European Workshop on Quantum Optics, Chudobín, April 30 - May 3, 1999
		Abstract: The generation of arbitrary single-mode quantum states from the vacuum by alternate coherent displacement and photon adding as well as the measurement of the overlap of a signal with an arbitrarily chosen quantum state are studied.
		With regard to implementations, the transformation of the quantum state of a traveling optical field at an array of beam splitters is considered, using conditional measurement.
		Allowing for arbitrary quantum states of both the input reference modes and the output reference modes on which the measurements are performed, the setup is described within the concept of two-port non-unitary transformation, and the overall non-unitary transformation operator is derived.
	www.acta.sav.sk /acta99/no4/contents.html (3507 words)

	Quantum Evolution, Johnjoe McFadden. Chapter 8
		Oblique quantum measurement (measurement that is slightly shifted from the previous state) is thereby able to rotate the angle of polarisation of photons.
		The inverse Zeno effect is described as inverse because its reverse, the quantum Zeno effect (which was described first, by Misra and Sudarshan of the University of Texas in 1977) describes how continuous measurement can freeze the dynamics of a quantum system.
		Both the quantum Zeno effect and the inverse Zeno effect are really aspects of the same phenomenon: the ability of quantum measurement to interact with, and shape the dynamics of a system.
	www.geneticengineering.org /evolution/mcfaddenc8.html (1865 words)

	Nonlinear quantum optical couplers (Site not responding. Last check: 2007-10-13)
		Such nonlinear quantum optical devices could allow one to generate and manipulate nonclassical light and to control light by light on quantum level.
		In quantum optics a downconversion process is an example of such unstable system as the pump photons decay into two photons of lower frequencies.
		The setup resembles the one discussed above in the context of quantum Zeno effect and shows that quantum Zeno effects and quantum interference are closely related physical concepts.
	rco.upol.cz /optics/research/couplers/couplers.htm (1342 words)

	When watching boils the pot
		This is known as the 'quantum Zeno effect', after the Greek philosopher Zeno of the fourth century BC, who specialized in devising puzzles and paradoxes.
		One of the revelations of quantum theory, which was developed in the early twentieth century, is that at very small scales -- for objects the size of atoms, say -- the act of observation inevitably affects what is observed.
		Zeno argued that it should be impossible for the swift-footed Achilles to overtake a lumbering tortoise that starts first in a race.
	www.mindswap.org /2002/nature/000601-9.xml (644 words)

	[No title] (Site not responding. Last check: 2007-10-13)
		The use of the Zeno effect for correcting errors in quantum computers was first suggested by Zurek \cite{Zurek}, and it is a part of a scheme recently proposed by Barenco {\it at el.} \cite{BBDEJM}.
		In this case we can omit the last part of the procedure since the quantum Zeno effect requires only correlation with some external system, and therefore, the observation of the state of the test particle is not necessary.
		It also cannot help if the main cause of the decoherence is some spontaneous decay process, since the quantum Zeno effect does not take place when the time interval between the measurements is larger than the characteristic time for which the exponential decay approximation is applicable.
	www.tau.ac.il /~quantum/publicat/papers/err-corr.txt (2982 words)

	Weak Gravity, MOND, and State Vector Reduction
		One of the most intriguing effects of state vector reduction is the Quantum Zeno Effect, where repeated measurements of a quantum system are shown to result in a suppression of the time evolution of the wave function.
		The effect is due to the fact that perturbations in quantum mechanics always show up as the square of the wave function.
		The second requirement of the Quantum Zeno Effect is that the wave function collapse rate has to be fast enough, compared to the rate at which perturbation theory fails.
	brannenworks.com /PenGrav.html (1060 words)

	[No title]
		In this theory the effects of mental action on brain activity is achieved by a Quantum Zeno Effect that is not weakened by decoherence.
		It is indeed usually thought that coherence is the essence of quantum theory, and that all quantum effects depend upon it.
		The drop-off of the interference effects is represented by the fact that the density matrix of the pointer/cat changes from one corresponding to a quantum superposition of the two states to one that represents a mixture.
	www-physics.lbl.gov /~stapp/deco.txt (2204 words)

	Luboš Motl's reference frame: Interaction-free measurements
		Zeno was apparently unaware of the fact that "0 times infinity" can give a finite result.
		If someone is convinced that the "counterfactual computation" can circumvent some problems in quantum computing and either reduce the error rate or decoherence, the most obvious way to use this insight is to build a working and large enough quantum computer.
		And it was actually some mis conception of quantum mechanics, not the violation of the basic principle of QM that all measurements involve interactions.
	motls.blogspot.com /2006/02/interaction-free-measurements.html (1395 words)

	Quantum Evolution, Johnjoe McFadden. Chapter 10
		Whereas in the light and sunglasses experiment, we rotated the angle of polarisation of light by quantum measurements performed by a series of Polaroid lenses; in the quantum proto-cell, it was a series of proto-enzymes that performed the quantum measurements.
		In the light experiment, it was our observation of light passing through the horizontal lens that performed the final irreversible act of measurement that amplified the quantum system to the classical realm; but in the proto-cell it was the emergence of the self-replicator that nailed the system to the classical world.
		Quantum measurements by proto-enzymes along the route to the self-replicator laid down a series of stepping stones that led to the emergence of life.
	www.surrey.ac.uk /qe/C10.htm (930 words)

	sciforums.com - More Zeno...
		In the fifth century BC, the Greek philosopher Zeno proposed a series of logical paradoxes that demonstrate the impossibility of motion.
		Now it seems that this effect (and its recently discovered converse, the anti-Zeno effect) can be understood simply as a particular instance of quantum propagation.
		We show that the Zeno and the anti-Zeno effects are two particular examples of quantum propagation depending on the effective spectrum of down-converted modes.
	www.sciforums.com /showthread.php?t=8971 (214 words)

	[No title]
		As you know, THE major hurdle that any quantum theory of mind faces is the fact that decoherence effects would appear, on the face of it, to obliterate any coherence effects that extend over any macroscopic portion of a human brain.
		Any viable quantum theory of mind must therefore explain in a satisfactory way how quantum theory could play a key role in the macroscopic brain activities associated with our conscious experiences in the face of this huge tendency for decoherence.
		But to get a quantum theory of mind we need to retain the conscious observers that quantum physicists had already found to be a natural part of quantum theory.
	www-physics.lbl.gov /~stapp/comment.txt (2614 words)

	Quantum Anti-Zeno effect? (Site not responding. Last check: 2007-10-13)
		They speak of the feasibiliry of AntiZeno Effect (AZE) in atomic decays, and explicitly it is said that some variant "takes place in systems that decay near threshold".
		I'd hear the opinion of the people in the newsgroup both about the general quality of the QZE/AZE calculations and on the feasibility of passing them from the atomic scale to the nuclear scale.
		I have not found any references to experiments on the anti-zeno effect for nuclear decays, neither beta not alpha.
	www.lns.cornell.edu /spr/2003-09/msg0053774.html (172 words)

	[No title]
		Zeno did not consider that an endless series could have a finite sum.
		Their work will appear in Physical Review A. The reason for the Zeno effect lies at the heart of quantum physics, which states that the energy of an atom moving between two energy states is somewhat uncertain and that (for short intervals) the uncertainty grows over time.
		To observe the Zeno effect, the NIST team confined 5,000 beryllium ions in an electromagnetic trap and exposed them for 256 milliseconds to a radio frequency that bumps beryllium ions to a higher, excited energy state.
	www.textfiles.com /bbs/KEELYNET/BIOLOGY/mind11.asc (1125 words)

	Quantum Interrogation
		Just as we were able in the quantum Zeno example to convert a string of elements into a cycle involving the same element again and again, here we can do the same thing, though the result might look a little different.
		Therefore, combining such an input with a quantum object, one is able to transfer the quantum superposition of the latter onto the former.
		In other words, one could make superpositions of "bunches" of photons; for example, one could prepare a pulse of light with an average of 20 photons in it, all of whom were horizontal, or all of whom were vertical, and yet until a measurement was made, none of them would have a definite polarization.
	www.physics.uiuc.edu /people/Kwiat/Interaction-Free-Measurements.htm (3071 words)

	Many Fates Resonance Zeno Clover
		Although the absolute effect sizes are quite small, of the order of 10^(&endash;4) bits deviation per bit processed, over the huge databases accumulated the composite effect exceeds 7 sigma (p = 3.5 x 10^(&endash;13)).
		Most other secondary parameters tested are found to have little effect on the scale and character of the results, with one important exception: studies performed using fully deterministic pseudorandom sources, either hard-wired or algorithmic, yield null overall mean shifts, and display no other anomalous features.
		At the Middle Level of Correlations and at the Highest Level of Simplex Physics, the interactions are Quantum Versions of generalizations of Cellular Automata.
	www.valdostamuseum.org /hamsmith/ManyFates.html (2474 words)

	ePrintsUQ - High-efficiency Quantum Interrogation Measurements via the Quantum Zeno Effect
		The phenomenon of quantum interrogation allows one to optically detect the presence of an absorbing object, without the measuring light interacting with it.
		In an application of the quantum Zeno effect, the object inhibits the otherwise coherent evolution of the light, such that the probability that an interrogating photon is absorbed can in principle be arbitrarily small.
		We have also predicted and experimentally verified a previously unsuspected dependence on loss; efficiencies of up to 73% were observed and the feasibility of efficiencies up to 85% was demonstrated.
	eprint.uq.edu.au /archive/00000677 (187 words)

	Strongly Coupled Quantum and Classical Systems and Zeno's Effect - Ph (ResearchIndex)
		Abstract: A model interaction between a two-state quantum system and a classical switching device is analysed and shown to lead to the quantum Zeno e#ect for large values of the coupling costant #.
		A minimal piecewise deterministic random process compatible with the Liouville equation is described, and it is shown that # -1 can be interpreted as the jump frequency of the classical device.
		Mathematics Of The Quantum Zeno Effect - Andreas Schmi Dt
	citeseer.ist.psu.edu /263943.html (666 words)

	DECOHERENCE AND QUANTUM MEASUREMENTS (Site not responding. Last check: 2007-10-13)
		The quantum measurement problem is one of the most fascinating and challenging topics in physics both theoretically and experimentally.
		The book deals not only with the measurement processes (including imperfect measurements) but also with related interference and mesoscopic phenomena — by means of general arguments — of solvable models and of numerical simulations.
		The quantum Zeno effect and the issue of irreversibility are also discussed.
	www.worldscibooks.com /physics/3420.html (162 words)

	Quantum bomb disposal
		Yet according to quantum theory, because light is both wave and particle, a photon can have a ghostly influence on itself.
		This trick is named after Zeno, the Greek philosopher of the fourth century BC renowned for his relish of paradoxes.
		The effect holds even in the case of vanishingly small interaction strengths, if the measurements are made often enough.
	www.mindswap.org /2002/nature/991216-3.xml (640 words)

	Zeno's paradox and quantum physics (Site not responding. Last check: 2007-10-13)
		Zeno did not consider that an endless series
		They called this surprising phenomenon the quantum Zeno effect.
		To observe the Zeno effect, the NIST team confined 5,000 beryllium
	www.unexplainable.net /artman/publish/printer_617.shtml (542 words)

	Kip Ingram Online :: Team Demonstrates Quantum Zeno Effect (Site not responding. Last check: 2007-10-13)
		A research team at The University of Texas at Austin has demonstrated both the quantum Zeno effect and the anti-quantum Zeno effect in the lab.
		Under normal circumstances quantum tunneling would cause the atoms to gradually slip out of the wave.
		The findings may help address a nagging issue associated with quantum computing: the tendency of quantum systems to "decohere" (that is, to drift out of a well-defined state).
	www.kipingram.com /index.php?p=101&c=1 (135 words)

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