Li Nicky Kai Hong, Huber Marcus, Friis Nicolai
Atominstitut, Technische Universität Wien, Stadionallee 2, 1020 Vienna, Austria.
Vienna Center for Quantum Science and Technology, TU Wien, 1020 Vienna, Austria.
npj Quantum Inf. 2025;11(1):50. doi: 10.1038/s41534-025-00990-6. Epub 2025 Mar 19.
Certifying entanglement is an important step in the development of many quantum technologies, especially for higher-dimensional systems, where entanglement promises increased capabilities for quantum communication and computation. A key feature distinguishing entanglement from classical correlations is the occurrence of correlations for complementary measurement bases. In particular, mutually unbiased bases (MUBs) are a paradigmatic example that is well-understood and routinely employed for entanglement certification. However, implementing unbiased measurements exactly is challenging and not generically possible for all physical platforms. Here, we extend the entanglement-certification toolbox from correlations in MUBs to arbitrary bases. This practically significant simplification paves the way for efficient characterizations of high-dimensional entanglement in a wide range of physical systems. Furthermore, we introduce a simple three-MUBs construction for all dimensions without using the Wootters-Fields construction, potentially simplifying experimental requirements when measurements in more than two MUBs are needed, especially in high-dimensional settings.
验证纠缠是许多量子技术发展中的重要一步，特别是对于高维系统而言，其中纠缠有望提升量子通信和计算的能力。区分纠缠与经典关联的一个关键特征是互补测量基下关联的出现。特别地，相互无偏基（MUBs）是一个得到充分理解且常用于纠缠验证的典型例子。然而，精确实现无偏测量具有挑战性，并非对所有物理平台都普遍可行。在此，我们将纠缠验证工具箱从相互无偏基中的关联扩展到任意基。这一具有实际意义的简化为广泛物理系统中高维纠缠的高效表征铺平了道路。此外，我们引入了一种适用于所有维度的简单三相互无偏基构造，无需使用伍特斯 - 菲尔德构造，这在需要多于两个相互无偏基进行测量时，尤其是在高维情形下，可能会简化实验要求。
