Thermal state pointer can enormously improve the precision of weak measurement
Gang Li, Ming-Yong Ye, He‐Shan Song · arXiv (Cornell University) · 2015
In most studies on post-selected weak measurement, the zero-mean Gaussian state (i.e., pure state) is initialized as a pointer state. Recently, several theoretical studies give the limits that using fisher information metric, weak measurement amplification strategy can not outperform the standard metrology strategy. However, we show that the limits, especially for the imaginary part of weak value, is no longer tenable if thermal state is initialized as a pointer state. By adjusting the temperature, we can improve accuracy of the measurement precision.