Quantum Zeno effect on Quantum Discord

TL;DR

This paper investigates how the quantum Zeno effect influences quantum discord in two entangled qubits under frequent measurements, revealing conditions where discord reliably indicates Zeno transitions and highlighting measurement precision effects.

Contribution

It introduces an analysis of quantum discord dynamics under the quantum Zeno effect, emphasizing the role of measurement strength and initial entanglement configurations.

Findings

Quantum discord indicates Zeno to anti-Zeno transition points for weak measurements.

High-precision measurements cause discord to become indeterminate due to system disturbance.

Measurement parameters critically affect the evolution of quantum correlations.

Abstract

We examine the quantum Zeno effect on the dynamics of quantum discord in two initially entangled qubits which are subjected to frequent measurements via decoherent coupling with independent reservoirs. The links between characteristic parameters such as system bias, measurement time duration, strength of initial entanglement between the two qubit systems and the dynamics of quantum discord are examined in the case of two initial state configurations. For weak or unsharp measurements, the quantum discord, which is an intrinsically distinct entity from concurrence, serves as a reliable indicator of the crossover point in Zeno to anti-Zeno transitions. However at highly precise quantum measurements, the monitoring device interferes significantly with the evolution dynamics of the monitored system, and the quantum discord yields indeterminate values in a reference frame where the observer is not an active constituent of the subsystems.