A generalized framework for the quantum Zeno and anti-Zeno effects in the strong coupling regime

• Published in: Scientific reports Vol. 12; no. 1; p. 18652
• Main Authors: Khan, Ghazi, Soomro, Hudaiba, Baig, Muhammad Usman, Javed, Irfan, Chaudhry, Adam Zaman
• Format: Journal Article
• Language: English
• Published: London Nature Publishing Group UK 04.11.2022; Nature Publishing Group; Nature Portfolio
• Subjects: 639/766/483; 639/766/530; Behavior; Decay; Evolution; Humanities and Social Sciences; multidisciplinary; Oscillators; Science; Science (multidisciplinary)
• ISSN: 2045-2322; 2045-2322
• DOI: 10.1038/s41598-022-23421-4

It is well known that repeated projective measurements can either slow down (the Zeno effect) or speed up (the anti-Zeno effect) quantum evolution. Until now, studies of these effects for a two-level system interacting with its environment have focused on repeatedly preparing the excited state via projective measurements. In this paper, we consider the repeated preparation of an arbitrary state of a two-level system that is interacting strongly with an environment of harmonic oscillators. To handle the strong interaction, we perform a polaron transformation and then use a perturbative approach to calculate the decay rates for the system. Upon calculating the decay rates, we discover that there is a transition in their qualitative behaviors as the state being repeatedly prepared continuously moves away from the excited state and toward a uniform superposition of the ground and excited states. Our results should be useful for the quantum control of a two-level system interacting with its environment.