Quantum Zeno and Anti-Zeno Effect without Rotating Wave Approximation

TL;DR

This paper investigates how anti-rotating terms influence the quantum Zeno and anti-Zeno effects in a two-level system, revealing that the effects depend sensitively on the atomic transition frequency.

Contribution

It provides a detailed analysis of the anti-rotating terms' impact on QZE and AQZE without relying on the rotating wave approximation, using unitary transformation and perturbation theory.

Findings

Zeno time depends sensitively on atomic transition frequency.

Anti-rotating terms can enhance either QZE or AQZE depending on frequency.

The effect varies with the relation between atomic transition and environment spectrum.

Abstract

The effect of the anti-rotating terms on the short-time evolution and the quantum Zeno (QZE) and anti-Zeno (AQZE) effects is studied for a two-level system coupled to a bosonic environment. A unitary transformation and perturbation theory are used to obtain the electron self-energy, energy shift and the enhanced QZE or the AQZE, simultaneously. The calculated Zeno time depends on the atomic transition frequency sensitively. When the atomic transition frequency is smaller than the central frequency of the spectrum of boson environment, the Zeno time is prolonged and the anti-rotating terms enhance the QZE; when it is larger than that the Zeno time is reduced and the anti-rotating terms enhance the AQZE.