Quantum resources of the steady-state of three coupled qubits: Microscopic versus Phenomenological model

TL;DR

This paper compares microscopic and phenomenological models for three coupled qubits, revealing that the phenomenological approach fails to capture certain quantum resources like steering and Bell nonlocality, which are significant in the microscopic model.

Contribution

It provides a detailed comparison between microscopic and phenomenological models for quantum resources in three coupled qubits, including analytical expressions for steady-state quantum correlations.

Findings

Phenomenological model shows no steering or Bell nonlocality.

Microscopic model reveals significant quantum resources.

Quantum resources are strongly influenced by the third qubit.

Abstract

Quantum resources, such as entanglement, steering, and Bell nonlocality, are evaluated for three coupled qubits in the steady-state configuration. We employ the phenomenological master equation and the microscopic master equation to probe such quantum resources, which provide very different results depending on the system configuration. In particular, steering and Bell nonlocality are null within the phenomenological model, while they reach considerable values within the microscopic model. These results show that the phenomenological approach is not able to capture all quantum resources of the system. We also provide an analytical expression for the steady-state and quantum resources of the system composed of three coupled qubits in the zero temperature limit. Such results demonstrate that quantum resources between two qubits are strongly affected by the third qubit in a nontrivial way.