Quantum zeno effect and intracavity polarization filters

H. Rauch

Kazuki Koshino, Akira Shimizu

К. О. Седых, Сыч Денис Васильевич

Abstract Quantum Zeno effect concerns deterministic dynamics of a quantum system induced by a series of projective quantum measurements. Applying this effect in optics, one can achieve an arbitrary lossless transformation of linear polarization of light with help of linear polarizers. However, to demonstrate this effect in practice, we have to take into account unavoidable losses in each polarizer that limits probability of successful transformations. In this work, we theoretically study a realistic quantum Zeno effect with an optimal discrete set of polarizers and find the maximum success probability

Isabel Gonzalo, Miguel A. Porras, Alfredo Luis

Abstract We describe an experiment in which the rotation of the polarization of light propagating in an optically active water solution of D-fructose tends to be inhibited by frequent monitoring whether the polarization remains unchanged. This is an example of the Zeno effect that has remarkable pedagogical interest because of its conceptual simplicity, easy implementation, low cost, and because the same the Zeno effect holds at classical and quantum levels. An added value is the demonstration of the Zeno effect beyond typical idealized assumptions in a practical setting with real polarizers.

E. Brion, V. M. Akulin, D. Comparat +6 more

Adam Zaman Chaudhry

Repeated measurements can slow down (the quantum Zeno effect) or speed up (the quantum anti-Zeno effect) the temporal evolution of a quantum system. In this paper, a general treatment of the quantum Zeno and anti-Zeno effects is presented which is valid for an arbitrary system-environment model in the weak system-environment coupling regime. It is shown that the effective lifetime of a quantum state that is subjected to repeated projective measurements depends on the overlap of the spectral density of the environment and a generalized 'filter function'. This filter function depends on the system-environment Hamiltonian, the state of the environment, and the measurement being performed. Our general framework is then used to study explicitly the Zeno to anti-Zeno crossover behaviour for the spin-boson model where a single two-level system is coupled to a bosonic environment. It is possible to not only reproduce results for the usual population decay case as well as for the pure dephasing model, but to also study the regime where both decay and dephasing take place. These results are then extended to many two-level systems coupled collectively to the bosonic environment to further illustrate the importance of the correct evaluation of the effective decay rate.