300 research outputs found
Total Quantum Zeno effect and Intelligent States for a two level system in a squeezed bath
In this work we show that by frequent measurements of adequately chosen
observables, a complete suppression of the decay in an exponentially decaying
two level system interacting with a squeezed bath is obtained. The observables
for which the effect is observed depend on the the squeezing parameters of the
bath. The initial states which display Total Zeno Effect are intelligent states
of two conjugate observables associated to the electromagnetic fluctuations of
the bath.Comment: 5 pages, 3 figure
Effect of the measurement on the decay rate of a quantum system
We investigated the electron tunneling out of a quantum dot in the presence
of a continuous monitoring by a detector. It is shown that the Schr\"odinger
equation for the whole system can be reduced to new Bloch-type rate equations
describing the time-development of the detector and the measured system at
once. Using these equations we find that the continuous measurement of the
unstable system does not affect its exponential decay, ,
contrary to expectations based on the Quantum Zeno effect . However, the width
of the energy distribution of the tunneling electron is no more , but
increases due to the decoherence, generated by the detector.Comment: Additional explanations are added. Accepted for publications in Phys.
Rev. Let
Mathematics of the Quantum Zeno Effect
We present an overview of the mathematics underlying the quantum Zeno effect.
Classical, functional analytic results are put into perspective and compared
with more recent ones. This yields some new insights into mathematical
preconditions entailing the Zeno paradox, in particular a simplified proof of
Misra's and Sudarshan's theorem. We empahsise the complex-analytic structures
associated to the issue of existence of the Zeno dynamics. On grounds of the
assembled material, we reason about possible future mathematical developments
pertaining to the Zeno paradox and its counterpart, the anti-Zeno paradox, both
of which seem to be close to complete characterisations.Comment: 32 pages, 1 figure, AMSLaTeX. In: Mathematical Physics Research at
the Leading Edge, Charles V. Benton ed. Nova Science Publishers, Hauppauge
NY, pp. 111-141, ISBN 1-59033-905-3, 2003; revision contains corrections from
the published corrigenda to Reference [64
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