Quantum Zeno dynamics of qubits in a squeezed reservoir: effect of measurement selectivity

TL;DR

This paper investigates how frequent measurements can suppress or modify qubit decay in a squeezed reservoir, revealing differences between measurement types and extending analysis to two-qubit systems with Zeno and anti-Zeno effects.

Contribution

It demonstrates the impact of measurement selectivity on quantum Zeno dynamics in qubits within a squeezed reservoir, including numerical analysis and extension to two-qubit systems.

Findings

Suppression of exponential decay via frequent measurements depends on measurement type.

Differences in Zeno dynamics are significant between selective and non-selective measurements.

Both Zeno and anti-Zeno effects observed in two-qubit systems depending on initial states.

Abstract

A complete suppression of the exponential decay in a qubit (interacting with a squeezed vacuum reservoir) can be achieved by frequent measurements of adequately chosen observables. The observables and initial states (Zeno subspace) for which the effect occurs depend on the squeezing parameters of the bath. We show these_quantum Zeno dynamics_ to be substantially different for selective and non-selective measurements. In either case, the approach to the Zeno limit for a finite number of measurements is also studied numerically. The calculation is extended from one to two qubits, where we see both Zeno and anti-Zeno effects depending on the initial state. The reason for the striking differences with the situation in closed systems is discussed.