Thermal evolution of quantum steering, Bell nonlocality, and entropic uncertainty in a Heitler–London coupled spin system

Abstract

This study explores the behavior of quantum steering, Bell nonlocality, and the quantum-memory-assisted entropic uncertainty relation (QMA-EUR) in a bipartite Heisenberg spin system, incorporating Heitler–London (HL) coupling, Dzyaloshinsky–Moriya (DM) interaction, and an external magnetic field B. The HL coupling is essential in providing a framework for electron interactions, taking into account wave function overlap and exchange interactions, which are crucial for describing spin-based phenomena. The analysis investigates how these quantum properties are influenced by various factors, including relative spin–spin distance R, temperature T, and additional system parameters at thermal equilibrium. The results highlight key trends: an increase in temperature T leads to a reduction in quantum resources, while simultaneously increasing QMA-EUR. Bell nonlocality and quantum steering exhibit similar temperature-dependent behavior, and their responses to variations in the relative separation between spins R diverge from those of QMA-EUR. Additionally, strong magnetic fields are shown to weaken quantum resources. However, through careful optimization of parameters such as R, T, B, and the strength of the DM interaction, it is possible to enhance Bell nonlocality and quantum steering, while minimizing QMA-EUR. These insights are valuable for advancing quantum technologies, particularly those relying on spin-based quantum systems.