Protecting geometric quantum discord via partially collapsing measurements of two qubits in multiple bosonic reservoirs

Abstract

We study the dynamics of geometric quantum discord (GQD) between two qubits, each qubit interacting at the same time with K independent multiple bosonic reservoirs at zero temperature. In both weak and strong qubit–reservoirs coupling regimes, we find that the increase of the number K of reservoirs can induce the damped oscillation of GQD, and enhance the memory effects of the overall environment. And the Hilbert–Schmidt norm GQD (two-norm GQD) is always smaller than the trace norm geometric quantum discord (one-norm GQD). Therefore, the one-norm GQD is a better way to measure the quantum correlation. Finally, we propose an effective strategy to improve GQD by using partially collapsing measurements, and we find that the protection effect is better with the increase of the weak measurement strength.