Non-Markovian dynamics, dense coding capacity, and non-locality in coupled two-qubit systems interacting with bosonic thermal environments

This paper investigates the time evolution of several quantum properties for two coupled qubits under asymmetric dissipation, where only one qubit is directly influenced by the environment. We specifically analyze the dynamics of dense coding capacity, Bell nonlocality, non-Markovianity, and local and nonlocal information. In a second scenario, we extend this model by including a second interaction with a bosonic thermal reservoir. Our analysis demonstrates that the non-Markovian character of the system is enhanced by tuning system parameters, specifically the mixing and coupling strength of the intra-qubit interactions. We establish a relationship between Bell non-locality and dense coding capacity. Our results reveal that optimal dense coding efficiency coincides with the violation of Bell non-locality in the first model, but not the second, thus highlighting the influence of the second bath. We also investigate the dynamics of both local and non-local information. Our findings indicate that all information-related quantities are sensitive to variations in parameter mixing, coupling strength. However, a universal trend emerges, all analyzed quantities tend to vanish over time, regardless of parameter variations. Specifically, the degree of Bell non-locality and dense coding capacity eventually plateau at values below their classical limits. Notably, enhanced dense coding efficiency correlates with stronger non-Markovian effects, revealing a complex interplay between information transmission and quantum memory dynamics.