Quantumness Witnesses

Connecting quantum contextuality and genuine multipartite nonlocality with the quantumness witness

The Clauser-Horne-Shimony-Holt-type noncontextuality inequality and the Svetlichny inequality are derived from the Alicki-Van Ryn quantumness witness. Thus a connection between quantumness and quantum contextuality, and that between quantumness and genuine multipartite nonlocality, are established.

Quantumness tests and witnesses in the tomographic-probability representation

In view of the tomographic-probability representation of quantum states, we reconsider the approach to quantumness tests of a single system developed in [Alicki and Van Ryn 2008 J. Phys. A: Math. Theor. 41 062001]. For qubits we introduce a general family of quantumness witnesses which are operators depending on an extra parameter. Spin tomogram and dual spin tomographic symbols are used to study qubit examples and the test inequalities which are shown to satisfy simple relations within the framework of the standard probability theory.

Classical to quantum in large number limit

We construct a quantumness witness following the work of Alicki and van Ryn (AvR) in "A simple test of quantumness for a single system" [J. Phys. A: Math. Theor., vol. 41, 062001 (2008)]. The AvR test is designed to detect quantumness. We reformulate the AvR test by defining it for quantum states rather than for observables. This allows us to identify the necessary quantities and resources to detect quantumness for any given system. The first quantity turns out to be the purity of the system. When applying the witness to a system with even moderate mixedness the protocol is unable to reveal an…

Quantumness and Entanglement Witnesses

We analyze the recently introduced notion of quantumness witness and compare it to that of entanglement witness. We show that any entanglement witness is also a quantumness witness. We then consider some physically relevant examples and explicitly construct some witnesses.

具有电池显式的热力学见证物的贝尔后量子性

Battery-Explicit Thermodynamic Witnesses of Bell Post-Quantumness

该研究提出了一种具有电池显式的热力学见证物，用于检测贝尔后量子相关性，通过能量守恒的受控SWAP操作将单个激发路由到显式的两能级电池，从而将游戏的成功概率转化为电池电荷的均值，为本地、量子或非信号行为提供了热力学上限。

利用量子性监测分束器纠缠

Monitoring Beam Splitter Entanglement using Quantumness

实验通过平衡分束器混合两个独立压缩真空态产生纠缠，提出基于量子性Ξ的框架，通过比较混合前后Ξ值来评估实验缺陷，弥补了不可分性判据无法检测输入态无纠缠的不足。