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arXiv · 1312.6910

Quantum Fisher information for density matrices with arbitrary ranks

Jing Liu·Xiao-Xing Jing·Wei Zhong·Xiaoguang Wang
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Abstract

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 a infinite dimensional density matrix with a finite support. Besides, a matrix representation of the QFI is also given.

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Jing Liu, Xiao-Xing Jing, Wei Zhong, Xiaoguang Wang. 2013-12-25. Quantum Fisher information for density matrices with arbitrary ranks. https://doi.org/10.1088/0253-6102%2F61%2F1%2F08

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