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arXiv · 1308.5413

Determining eigenvalues of a density matrix with minimal information in a single experimental setting

Tohru Tanaka·Yukihiro Ota·Mitsunori Kanazawa·Gen Kimura·Hiromichi Nakazato·Franco Nori
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Abstract

Eigenvalues of a density matrix characterize well the quantum state's properties, such as coherence and entanglement. We propose a simple method to determine all the eigenvalues of an unknown density matrix of a finite-dimensional system in a single experimental setting. Without fully reconstructing a quantum state, eigenvalues are determined with the minimal number of parameters obtained by a measurement of a single observable. Moreover, its implementation is illustrated in linear optical and superconducting systems.

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Tohru Tanaka, Yukihiro Ota, Mitsunori Kanazawa, Gen Kimura, Hiromichi Nakazato, Franco Nori. 2013-11-25. Determining eigenvalues of a density matrix with minimal information in a single experimental setting. https://doi.org/10.1103/physreva.89.012117

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