Improvement of entanglement transfer by weak measurement and quantum measurement reversal in two parallel Heisenberg spin chains

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 mth 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. (paper)