Using the weak measurement (WM) and quantum measurement reversal (QMR) approach, robust state transfer and entanglement distribution can be realized in the spin-
21 Heisenberg chain. We find that the ultrahigh fidelity and long distance of quantum state transfer with certain success probability can be obtained using proper WM and QMR, i.e., the average fidelity of a general pure state from
80 to almost
100, which is almost size independent. We also find that the distance and quality of entanglement distribution for the Bell state and the general Werner mixed state can be obviously improved by the WM and QMR approach.
The effect of weak measurement (WM) and quantum measurement reversal (QMR) on the entanglement transfer in two parallel Heisenberg spin chains is investigated. We find that the entanglement transfer can be enhanced by the WM and QMR control for different N ( N is the length of each spin chain) and m ( m denotes the m th spin pair). More interestingly, we also find that, in the thermodynamic limit where the so-called phase-shift control is invalid, the WM and QMR control is instead very effective. So this investigation indicates that the WM and QMR approach has potential applications in quantum information processing based on the spin chain.