Quantum Entanglement Dynamics in Open Quantum Systems

This study presents the first comprehensive dataset on quantum entanglement dynamics in open quantum systems, recorded under the environmental noise profiles characteristic of the Tanzanian equatorial region between 2021 and 2022. The experimental apparatus, situated at the University of Dar es Salaam, employed spontaneous parametric down-conversion in a type-II beta-barium borate crystal to generate polarisation-entangled photon pairs. Tunable spectral filters and liquid-crystal variable retarders were used to engineer controlled Markovian and non-Markovian phase-damping channels, replicating diverse environmental conditions. The dataset comprises 48 CSV files systematically organised across three distinct reservoir spectral densities—Ohmic, sub-Ohmic, and super-Ohmic—each examined under varying coupling strengths. Time-stamped records of concurrence, purity, and negativity, along with associated uncertainties, provide a multi-metric characterisation of the system's state, enabling the disentanglement of genuine quantum correlations from classical mixing effects. A separate metadata file details experimental parameters including system–reservoir coupling constants, temperature, cut-off frequencies, and calibration constants. Data validation was performed through systematic comparison with exact analytical predictions for the Markovian limit, where observed decay curves for concurrence and logarithmic negativity showed high qualitative agreement with theoretical expectations, particularly in the early-time regime. This concordance confirms the integrity of the experimental apparatus and state-reconstruction protocol. The dataset enables validation of theoretical decoherence models under variable thermal and magnetic field fluctuations, offering a benchmark for quantum information processing in resource-limited settings. By systematically cataloguing entanglement evolution under both Markovian and non-Markovian regimes, the data support further research into error mitigation strategies and the development of robust quantum protocols for emerging quantum technologies.