

Preprint 4/2019
Improved quantum entropic uncertainty relations
Zhi-Hua Chen, Zhi-Hao Ma, Yunlong Xiao, and Shao-Ming Fei
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Submission date: 09. Jan. 2019
Pages: 16
published in: Physical review / A, 98 (2018) 4, art-no. 042305
DOI number (of the published article): 10.1103/PhysRevA.98.042305
Bibtex
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Abstract:
We study entropic uncertainty relations by using stepwise linear functions and quadratic functions.
Two kinds of improved uncertainty lower bounds are constructed: the state-independent
one based on the lower bound of Shannon entropy and the tighter state-dependent one based on
the majorization techniques. The analytical results for qubit and qutrit systems with two or three
measurement settings are explicitly derived, with detailed examples showing that they outperform
the existing bounds. The case with the presence of quantum memory is also investigated.