Improved quantum discord via weak measurement

We investigate the dynamical behavior of quantum discord with weak measurement under various environments. We find that the quantum discord closely relates to the interaction between qubits, measurement strength and the correlation rate between environments of qubits. The interaction results in oscillation of quantum discord and avoids quantum discord sudden death for certain initial states. The stronger the interaction is, more intense the oscillation is. The increase of measurement strength will lead to the decrease of quantum discord. The correlation rate also affects the quantum correlation significantly. Stronger correlation is favor to improve the quantum correlation between qubits. Not only the amplitude of quantum discord is increased, but also the time for zero quantum discord is greatly delayed.