1 Parameter estimation of quantum channels
Zhengfeng Ji, Guoming Wang, Runyao Duan, Yuan Feng, Mingsheng Ying · 2006
Abstract — The efficiency of parameter estimation of quantum channels is studied in this paper. We introduce the concept of programmable parameters to the theory of estimation. It is found that programmable parameters obey the standard quantum limit strictly; hence no speedup is possible in its estimation. We also construct a class of non-unitary quantum channels whose parameter can be estimated in a way the standard quantum limit is broken. I.