Equivalence Classes and Local Asymptotic Normality in System Identification for Quantum Markov Chains
Equivalence Classes and Local Asymptotic Normality in System Identification for Quantum Markov Chains
复制标题
量子马尔可夫链系统辨识中的等价类和局部渐近正态性
DOI:
10.1007/s00220-014-2253-0
复制
发表时间:
2014
影响因子:
2.4
通讯作者:
J. Kiukas
中科院分区:
文献类型:
--
作者:
M. Guţă;J. Kiukas
We consider the problem of identifying and estimating dynamical parameters of an ergodic quantum Markov chain, when only the stationary output is accessible for measurements. The starting point of the analysis is the fact that the knowledge of the output state completely fixes the dynamics up to an equivalence class of ‘coordinate transformation’ consisting of a multiplication by a phase and a unitary conjugation of the Kraus operators.Assuming that the dynamics depends on an unknown parameter, we show that the latter can be estimated at the ‘standard’ rate n−1/2, and give an explicit expression of the (asymptotic) quantum Fisher information of the output, which is proportional to the Markov variance of a certain ‘generator’. More generally, we show that the output is locally asymptotically normal, i.e., it can be approximated by a simple quantum Gaussian model consisting of a coherent state whose mean is related to the unknown parameter. As a consistency check, we prove that a parameter related to the ‘coordinate transformation’ unitaries has zero quantum Fisher information.
DOI:
10.1088/1751-8113/47/41/415302
发表时间:
2014
期刊:
Mathematical and Theoretical
影响因子:
--
作者:
Catana C
通讯作者:
Catana C
DOI:
10.48550/arxiv.1206.4956
发表时间:
2012
期刊:
--
影响因子:
--
作者:
Girotti F
通讯作者:
Girotti F
DOI:
10.48550/arxiv.1403.0116
发表时间:
2014
期刊:
--
影响因子:
--
作者:
Catana C
通讯作者:
Catana C