Thermal Local Quantum Information Beyond Entanglement in Two-Qubit NV Centers with External Control Parameters

The thermal behavior of quantum correlations is explored in a two-qubit system based on nitrogen-vacancy (NV) centers, using Local Quantum Fisher Information (LQFI), Local Quantum Uncertainty (LQU), and concurrence as quantifiers. These results show that entanglement, measured byconcurrence (CE), decays rapidly with increasing temperature, whereas coherence-based measures such as LQFI and LQU display greater resilience. The strength of zero-field splitting plays a key role in shaping quantum correlations, significantly suppressing entanglement at higher values while helping to preserve coherence. External magnetic and electric fields further influence these dynamics–magnetic fields tend to suppress entanglement, while electric fields accelerate its degradation. Dipole–dipole interactions enhance the initial quantum correlations but have a limited effect on their thermal decay. Overall, these findings underscore the robustness of coherence-based quantum resources and suggest that, while dipole–dipole coupling is more effective at regulating quantum correlations, optimal tuning of system parameters can significantly improve both the generation and preservation of these correlations at finite temperatures.