Quantum Zeno and Anti-Zeno Effects

Quantum systems are inherently probabilistic, and the characterization of an unstable or unknown quantum system is linked to a phenomenon of measurement. Generally unstable systems in nature exhibit a process of exponential decay.  The decay process instantaneously begins once the effect that has bought it to the instability has subsided. 

In quantum systems, we notice that there is a slight region of deviation from the exponential decay path that generally systems take. The Quantum Zeno effect, utilizes this phenomenon, in a rather prolific way to slow down the decay mechanism. This is done by repetitive measurements of the system without long exposures, which leads to fewer energy collections and in turn, makes us feel like we are actually stagnated in a planar spectrum of measurement (more like a linear approximation of the gradient at a point on a function, or oversampling in other terms). 

The anti-effect of this, that is the fact of performing measurement for longer periods of time, causes the decay faster is a counterexample of the quantum zero effect, or affectionately called the quantum anti-zero effect. It is also the case that by repetitive measurements of the same system, the system appears stagnated, more like a looking at the ceiling fan turn with our eye, we can barely spot any blades, but grab a camera with a large enough sampling speed, we can get individual details of each arm of the fan. In quantum systems, the same is done but in a rather destructive fashion.

Above is a video from Washington University in St.Louis to understand it more better!