Bounding the entanglement of a state from its spectrum
Universitat Autònoma de Barcelona（巴塞罗那自治大学）；Jagiellonian University（雅盖隆大学）；Universität Siegen（锡根大学）；ICREA – Institució Catalana de Recerca i Estudis Avançats（加泰罗尼亚研究与高等研究院）
Jofre Abellanet-Vidal, Guillem Müller-Rigat, Albert Rico, Anna Sanpera
We introduce a framework to upper bound the entanglement content of a bipartite quantum state from its spectrum alone. Using linear maps and their inverses, we derive rigorous constraints on the maximal entanglement that can be activated under global unitary transformations. We use as entanglement quantifiers the negativity and the Schmidt number; however, our framework is general and applies to any other entanglement measure. Our approach yields compact analytical sufficient criteria for bounding the entanglement of full-rank states in arbitrary dimensions and reveals new spectral constraints on Schmidt number witnesses.
Entanglement -- the coherent correlations between parties in a joint quantum system -- is well-understood and quantifiable in the two-dimensional, two-party case. Higher (>2)-dimensional entangled systems hold promise in extending the capabilities of various quantum information applications. Despite the utility of such systems, methods for quantifying high-dimensional entanglement are more limited and experimentally challenging. We review entanglement certification approaches and the large number of -- often difficult -- measurements required to apply them. We present a novel certification met…
Lower-bounding entanglement with nonlocality in a general Bell's scenario
University of Science and Technology of China（中国科学技术大学）；Hefei National Research Center for Physical Sciences at the Microscale（合肥微尺度物质科学国家研究中心）；School of Physical Sciences, University of Science and Technology of China（中国科学技术大学物理科学学院）；School of Physics and Optoelectronics Engineering, Anhui University（安徽大学物理与光电工程学院）；Hefei National Laboratory, University of Science and Technology of China（中国科学技术大学合肥国家实验室）
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