Protecting quantum correlations of negative quantum states using weak measurement under non-Markovian noise

Abstract

The weak measurement (WM) and quantum measurement reversal (QMR) are crucial in protecting the collapse of quantum states. The idea of WM and QMR has recently been used to protect and enhance quantum correlations and universal quantum teleportation (UQT) protocol. Here, we study the quantum correlations, maximal fidelity, and fidelity deviation of the two-qubit negative quantum states developed using discrete Wigner functions with (without) WM and QMR. To take into account the effect of a noisy environment, we evolve the states via non-Markovian amplitude damping and random telegraph noise quantum channels. To benchmark the performance of negative quantum states, we calculate their success probability. We compare our results with the two-qubit maximally entangled Bell state. Interestingly, we observe that some negative quantum states perform better with WM and QMR than the Bell state for different cases under evolution via noisy quantum channels.

Efficient entanglement enhancement of partially entangled pairs

“…The experimental implementation of this scheme is reported in [22]. Moreover, weak measurements have been widely employed to enhance entanglement in the presence of noise [23][24][25][26][27][28][29][30]. However, it is not feasible to extract a maximally entangled state from a single copy of a mixed state using local purification protocols [31,32].…”