Dynamics of Two-Qubit Correlations in a Double Quantum Dot System Supported by Spin–Spin Interactions Under Intrinsic Decoherence

This study investigates the dynamics of two-qubit correlations in a double quantum dot (QD) containing an electron and two charge-spin configurations under the influence of Rashba interaction, the Dzyaloshinsky–Moriya interaction, and an external magnetic field. The dynamics of two-qubit correlations, particularly those of local quantum Fisher information (LQFI) and local quantum uncertainty (LQU), are compared with those of log negativity. The correlation dynamics are analysed under the effects of Dzyaloshinsky–Moriya interaction, Rashba spin–orbit coupling, electron tunnelling strength, Zeeman spin-splitting coupling, and intrinsic decoherence. Importantly, in the absence of intrinsic electron QD qubit decoherence, it is found that weak couplings within the electron QD qubit system have a high capacity to create equal LQFI and LQU two-qubit correlations, as well as log-negativity entanglement. Furthermore, it is found that an increase in Zeeman spin splitting and the tunnelling effect of two electrons decreases the ability of the other couplings, DM spin–orbit and Rashba spin–orbit interactions, to generate Wigner–Yanase–Fisher correlation and entanglement, and the opposite is also true. The generation of electron-QD qubit correlations exhibits decaying oscillatory dynamics, especially when decoherence is considered. Additionally, the LQFI and LQU display different correlations, and the sudden death and birth phenomena of entanglement occur. Moreover, the phenomena of decaying oscillatory dynamics, as well as the sudden death and birth of entanglement, depend on the electron-QD-qubit couplings. These electron-QD-qubit correlations provide the quantum dot system with promising features for establishing quantum technologies.