(英) |
We address quantum parameter estimation problems when some of the parameters are of no interest to be estimated. In classical statistics, these irrelevant parameters, which appear in the statistical model, are called nuisance parameters and it is known how much estimation errors become worse in the presence of nuisance parameters. However, little is known regarding the effects of nuisance parameters in quantum-state estimation problem. The main contribution of this paper is to formulate nuisance parameter problem for the quantum state estimation theory. We then extend methods known in classical statistics to the quantum domain to derive the precision bound in the presence of nuisance parameters. |