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Laser Physics Letters

Coherence estimation of quantum superposition states

Chengyang Zhang, Zhihua Guo, Ying Yang, Huaixin Cao

Published Mar 1, 2025• 3 citations
Publisher

Abstract

Abstract Quantum coherence is a fundamental resource in quantum information science and one of the most distinctive features of quantum mechanics. In this paper, we derive a tight upper bound for the coherence of the superposition composed of two orthogonal states using ℓ 1 -norm coherence measure, demonstrating that our upper bound is tighter than the one presented by Yue et al (2017 Sci. Rep. 7 4006). Furthermore, we extend the result to the superposition of n orthogonal states and establish the optimal upper bound for its coherence. Our results provide a more accurate estimate of the coherence of the superposition state.

DOI
10.1088/1612-202x/adba40

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