Simple computer model for the quantum Zeno effect

We analyze the influence of the finite duration of the measurement on the quantum Zeno effect, using a simple model of the measurement. It is shown that the influence of the finite duration of the measurement is uninportant when this duration is small compared to the duration of the free evolution between the measurements.

Measurement quantum mechanics, the theory of a quantum system which undergoes a measurement process, is introduced by a loop of mathematical equivalencies connecting previously proposed approaches. The unique phenomenological parameter of the theory is linked to the physical properties of an informational environment acting as a measurement apparatus which allows for an objective role of the observer. Comparison with a recently reported experiment suggests how to investigate ...

As of October 2006, there were approximately 535 citations to the seminal 1977 paper of Misra and Sudarshan that pointed out the quantum Zeno paradox (more often called the quantum Zeno effect). In simple terms, the quantum Zeno effect refers to a slowing down of the evolution of a quantum state in the limit that the state is observed continuously. There has been much disagreement as to how the quantum Zeno effect should be defined and as to whether it is really a paradox, re...

We present a simulation of the quantum Zeno effect (QZE) on a quantum computer as an example of the relation between this effect and the bang-bang decoupling method in control theory. Although the true QZE can not be strictly implemented on a quantum computer where all the operations, except the final measurements, must be unitary ones, we can simulate it by coupling the system to a number of ancillas and replacing the projective measurements of the QZE by suitable unitary ga...

In this paper we investigate the quantum Zeno and anti-Zeno effects without using any particular model of the measurement. Making a few assumptions about the measurement process we derive an expression for the jump probability during the measurement. From this expression the equation, obtained by Kofman and Kurizki [Nature (London) 405, 546 (2000)] can be derived as a special case.

In 1977, Mishra and Sudarshan showed that an unstable particle would never be found decayed while it was continuously observed. They called this effect the quantum Zeno effect (or paradox). Later it was realized that the frequent measurements could also accelerate the decay (quantum anti-Zeno effect). In this paper we investigate the quantum Zeno effect using the definite model of the measurement. We take into account the finite duration and the finite accuracy of the measure...

A quantum system being observed evolves more slowly. This `'quantum Zeno effect'' is reviewed with respect to a previous attempt of demonstration, and to subsequent criticism of the significance of the findings. A recent experiment on an {\it individual} cold trapped ion has been capable of revealing the micro-state of this quantum system, such that the effect of measurement is indeed discriminated from dephasing of the quantum state by either the meter or the environment.

This is a primer on the quantum Zeno effect, addressed to students and researchers with no previous knowledge on the subject. The prerequisites are the Schr\"odinger equation and the von Neumann notion of projective measurement.

We suggest a quantum simulator that allows to study the role of memory effects in the dynamics of open quantum systems. Our proposal is based on a bipartite quantum system consisting, for simplicity, of a harmonic oscillator and a few-level system; it exploits the formal analogy between dissipation and quantum measurements. The interaction between the subsystems gives rise to quantum Zeno dynamics, and the dissipation strength experienced by the harmonic oscillator can be tun...

If frequent measurements ascertain whether a quantum system is still in its initial state, transitions to other states are hindered and the quantum Zeno effect takes place. However, in its broader formulation, the quantum Zeno effect does not necessarily freeze everything. On the contrary, for frequent projections onto a multidimensional subspace, the system can evolve away from its initial state, although it remains in the subspace defined by the measurement. The continuing ...