We provide a new expression of the quantum Fisher information(QFI) for a general system.Utilizing this expression,the QFI for a non-full rank density matrix is only determined by its support.This expression can bring ...We provide a new expression of the quantum Fisher information(QFI) for a general system.Utilizing this expression,the QFI for a non-full rank density matrix is only determined by its support.This expression can bring convenience for an infinite-dimensional density matrix with a finite support.Besides,a matrix representation of the QFI is also given.展开更多
基金Supported by the National Fundamental Research Program of China under Grant No.2012CB921602the National Natural Science Foundation of China under Grants Nos.11025527 and 10935010
文摘We provide a new expression of the quantum Fisher information(QFI) for a general system.Utilizing this expression,the QFI for a non-full rank density matrix is only determined by its support.This expression can bring convenience for an infinite-dimensional density matrix with a finite support.Besides,a matrix representation of the QFI is also given.
