在量子信息分裂中利用局部测量提高量子参数估计

我们利用多体量子纠缠信道在环境噪声中实现了关于量子相位参量的信息分裂.这个量子信息分裂方案是指从一个发送端,人们将含有信息的任意量子态传输到多个接收端,然后利用么正测量在任意一个接收端上还原量子参量信息.我们发现,在退振幅阻尼噪声通道下,合理引入局部测量能提高量子参量估计精度.当环境表现为马尔科夫性时,经过量子信息分裂,量子参量估计精度的动力学演化会呈现单调衰减趋势.当环境具有一定记忆效应时,其演化会呈现振荡起伏行为.

Improving Quantum Parameter Estimation by Partial Measurements in Quantum Information Splitting

We realize the quantum information splitting with respect to phase parameter through the quantum channel with multi-partite entangled states in the condition of the environmental noise. The protocol of quanutm information splitting is that the information encoded in quantum parameters from a sender can be recovered at any one of many receivers by means of measurements. It is found that a general partial measurement can help to enhance the quantum Fisher information under the influence of amplitude-damping noise. In the Markovian case, the values of quantum Fisher information are decreased monotically.In the non-Markovian case, there exists the oscillation of quantum Fisher information.