Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

Czechoslovak Journal of Physics

Unstable systems and repeated measurements III. Example (homogeneous chamber), conjecture for the general case and discussion

Pavel Exner

Published Apr 1, 1977• 1 citation
Publisher
DOI
10.1007/bf01596727

Related papers

Unstable systems and repeated measurements

Pavel Exner

Czechoslovak Journal of Physics•Feb 1, 1977•5 citations

Repeated Measurements on Unstable System

Pavel Exner

Springer eBooks•Jan 1, 1985•0 citations

Lorentz-Invariant Localization for Elementary Systems

Juan Carlos Gallardo, Andrés J. Kálnay, Salomon Risemberg

Philips has axiomatically defined sets of localized states which are Lorentz-invariant (while Newton-Wigner sets of localized states are not) and has divided these sets into three classes. Philips's conjecture concerning spin-zero localized states, namely, that the postulates define the sets of localized states in a unique way, is proved to be incorrect by finding a class-III set that satisfies Philips's postulates. Philips's work is discussed and his calculations (spin-zero case) are repeated without using some (explicit and implicit) unnecessary hypotheses. These calculations are also extended to the spin-\textonehalf{} case, for which it is proved that there are only class-III sets of localized states. The results are discussed. Incidentally, an explicit form of the effects induced by a Lorentz transformation on representation space is found for both the spin-zero and spin-\textonehalf{} cases.

Physical Review•Jun 25, 1967•21 citations

Zeno effect preventing Rabi transitions onto an unstable energy level

Jürgen Audretsch, Michael B. Mensky, Alexander D Panov

We consider a driven 2-level system with one level showing spontaneous decay to an otherwise uncoupled third level. Rabi transitions to the unstable level are strongly damped. This simple configuration can be used to demonstrate and to explore the quantum Zeno effect leading to a freezing of the system to the initial level. A comparison with repeated projection measurements is given. A treatment within a phenomenological theory of continuous measurements is sketched. The system visualizes the important role of null measurements (negative result measurements) and may serve as a good example for a truly continuous measurement. 1 1

•Jan 1, 1999•5 citations

On the description of multiple measurements of an unstable state

Mikhail Aleksandrovich Braun, K. Urbanowski

Foundations of Physics•Apr 1, 1992•6 citations

MANY SUCCESSIVE MEASUREMENTS AND EXPONENTIAL DECAY

K. Urbanowski

A multiple repeated measurement of the unstable state evolving in time is discussed. We show that there is no decay in the limit of continuous measurements and there is a purely exponential decay law in other cases. We also give formulae for the effective decay width in the cases of very short, intermediate, relatively long and very long time intervals separating successive measurements. Our results are compared with the Weisskopf-Wigner formula for weak decays. Based on our model of a measurement, we show that the decay width does not depend on properties of the real detectors in practice.

International Journal of Modern Physics A•Mar 10, 1991•11 citations
Philips has axiomatically defined sets of localized states which are Lorentz-invariant (while Newton-Wigner sets of localized states are not) and has divided these sets into three classes. Philips's conjecture concerning spin-zero localized states, namely, that the postulates define the sets of localized states in a unique way, is proved to be incorrect by finding a class-III set that satisfies Philips's postulates. Philips's work is discussed and his calculations (spin-zero case) are repeated without using some (explicit and implicit) unnecessary hypotheses. These calculations are also extended to the spin-\textonehalf{} case, for which it is proved that there are only class-III sets of localized states. The results are discussed. Incidentally, an explicit form of the effects induced by a Lorentz transformation on representation space is found for both the spin-zero and spin-\textonehalf{} cases.
We consider a driven 2-level system with one level showing spontaneous decay to an otherwise uncoupled third level. Rabi transitions to the unstable level are strongly damped. This simple configuration can be used to demonstrate and to explore the quantum Zeno effect leading to a freezing of the system to the initial level. A comparison with repeated projection measurements is given. A treatment within a phenomenological theory of continuous measurements is sketched. The system visualizes the important role of null measurements (negative result measurements) and may serve as a good example for a truly continuous measurement. 1 1
A multiple repeated measurement of the unstable state evolving in time is discussed. We show that there is no decay in the limit of continuous measurements and there is a purely exponential decay law in other cases. We also give formulae for the effective decay width in the cases of very short, intermediate, relatively long and very long time intervals separating successive measurements. Our results are compared with the Weisskopf-Wigner formula for weak decays. Based on our model of a measurement, we show that the decay width does not depend on properties of the real detectors in practice.