Effect of partial-collapse measurement on quantum entanglement in noninertial frames

An efficient method is proposed to improve two-qubit entanglement under the action of noise channel in noninertial frames by using partial-collapse measurement. We focus on the influence of partial-collapse measurement on entanglement for different noise channels in noninertial frames. It is shown that entanglement can be enhanced greatly for phase-flip, phase-damping, depolarizing and amplitude-damping channels. We obtain the optimal concurrence for the four noise channels, respectively. Moreover, ’entanglement sudden death’ can be avoided for amplitude-damping environment. Our work provides a novel method to improve quantum entanglement under both noise environment and Unruh effect and exhibits the ability of partial-collapse measurement as an important technique in relativistic quantum information.