Measuring coherence of quantum measurements
Measuring coherence of quantum measurements
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DOI：
10.1103/physrevresearch.1.033020
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发表时间：
2019-03
影响因子：
4.2
通讯作者：
V. Cimini;I. Gianani;M. Sbroscia;J. Sperling;M. Barbieri
中科院分区：
文献类型：
--
作者：
V. Cimini;I. Gianani;M. Sbroscia;J. Sperling;M. Barbieri
量子态的叠加是物理学的核心，最近被发现可以作为量子信息协议的通用资源，定义了量子相干的概念。在这方面的贡献，我们报告其补充概念，量子测量的相干性的实施。通过设计一个可访问的标准，在任何经典的统计理论中成立，我们证明，非对易量子测量违反了这一约束，使之有可能进行基于测量的量子相干性的操作评估。特别是，我们验证了单个光子量子比特的偏振测量，一个量子信息单元的基本载体，已经与经典的，即，不相干的，测量设备的模型。因此，我们实现了一种方法，使我们能够定量地证明哪些量子测量遵循与经典理论预期的根本不同的统计规律，同时，在量子信息技术资源的现代框架内量化它们的有用性。
The superposition of quantum states lies at the heart of physics and has been recently found to serve as a versatile resource for quantum information protocols, defining the notion of quantum coherence. In this contribution, we report on the implementation of its complementary concept, coherence from quantum measurements. By devising an accessible criterion which holds true in any classical statistical theory, we demonstrate that noncommutative quantum measurements violate this constraint, rendering it possible to perform an operational assessment of the measurement-based quantum coherence. In particular, we verify that polarization measurements of a single photonic qubit, an essential carrier of one unit of quantum information, are already incompatible with classical, i.e., incoherent, models of a measurement apparatus. Thus, we realize a method that enables us to quantitatively certify which quantum measurements follow fundamentally different statistical laws than expected from classical theories and, at the same time, quantify their usefulness within the modern framework of resources for quantum information technology.