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Related papers: Robust self-testing of two-qubit states

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We study dynamics of nonclassical correlations by exactly solving a model consisting of two atomic qubits with spontaneous emission. We find that the nonclassical correlations defined by different measures give different qualitative…

Quantum Physics · Physics 2012-02-01 Ming-Liang Hu , Heng Fan

Self-testing is a powerful certification of quantum systems relying on measured, classical statistics. This paper considers self-testing in bipartite Bell scenarios with small number of inputs and outputs, but with quantum states and…

Quantum Physics · Physics 2024-03-27 Jurij Volčič

Bell inequalities constitute a key tool in quantum information theory: they not only allow one to reveal nonlocality in composite quantum systems, but, more importantly, they can be used to certify relevant properties thereof. We provide a…

Quantum Physics · Physics 2020-01-22 F. Baccari , R. Augusiak , I. Šupić , J. Tura , A. Acín

We consider a subclass of bipartite CHSH-type Bell inequalities. We investigate operations, which leave their Tsirelson bound invariant, but change their classical bound. The optimal observables are unaffected except for a relative rotation…

Quantum Physics · Physics 2014-10-10 Michael Epping , Hermann Kampermann , Dagmar Bruß

Quantum nonlocality has recently been intensively studied in connection to device-independent quantum information processing, where the extremal points of the set of quantum correlations play a crucial role through self-testing. In most…

Quantum Physics · Physics 2020-02-13 Satoshi Ishizaka

Self-testing of quantum devices based on observed measurement statistics is a method to certify quantum systems using minimal resources. In Ref. [Phys. Rev. \textbf{A} 101, 032106 (2020)], a scheme based on observing measurement statistics…

Quantum Physics · Physics 2024-12-03 Chellasamy Jebarathinam , Gautam Sharma , Sk Sazim , Remigiusz Augusiak

We relate the the distinguishability of quantum states with their robustness of the entanglement, where the robustness of any resource quantifies how tolerant it is to noise. In particular, we identify upper and lower bounds on the…

Quantum Physics · Physics 2025-12-24 Debarupa Saha , Kornikar Sen , Chirag Srivastava , Ujjwal Sen

A quantum state can be characterized from the violation of a Bell inequality. The well-known CHSH inequality for example can be used to quantify the fidelity (up to local isometries) of the measured state with respect to the singlet state.…

Correlation self-testing of quantum theory involves identifying a task or set of tasks whose optimal performance can be achieved only by theories that can realise the same set of correlations as quantum theory in every causal structure.…

Quantum Physics · Physics 2025-11-06 Kuntal Sengupta , Mirjam Weilenmann , Roger Colbeck

We assess the quality of a source of allegedly pure two-qubit states using both standard tomography and methods inspired by device-independent self-testing. Even when the detection and locality loopholes are open, the latter methods can…

Quantum Physics · Physics 2019-08-08 Koon Tong Goh , Chithrabhanu Perumangatt , Zhi Xian Lee , Alexander Ling , Valerio Scarani

Bell nonlocality as a resource for device independent certification schemes has been studied extensively in recent years. The strongest form of device independent certification is referred to as self-testing, which given a device certifies…

Quantum Physics · Physics 2021-12-15 Shubhayan Sarkar , Debashis Saha , Jędrzej Kaniewski , Remigiusz Augusiak

In this paper, we show that coherence witness for a single qubit itself yields conditions for nonlocality and entanglement inequalities for multiqubit systems. It also yields a condition for quantum discord in two--qubit systems. It is…

Quantum Physics · Physics 2022-04-25 Sooryansh Asthana

In contrast to the wide-spread opinion that any separable quantum state satisfies every classical probabilistic constraint, we present a simple example where a separable quantum state does not satisfy the original Bell inequality although…

Quantum Physics · Physics 2007-05-23 Elena R. Loubenets

We compare schemes for testing whether two parties share a two-qubit singlet state. The first, standard, scheme tests Braunstein-Caves (or CHSH) inequalities, comparing the correlations of local measurements drawn from a fixed finite set…

Quantum Physics · Physics 2025-05-13 George Cowperthwaite , Adrian Kent

Based on the violation of Bell inequalities, we can verify quantum random numbers by examining the correlation between device inputs and outputs. In this paper, we derive the maximum quantum value of the parity-CHSH inequality for a…

Quantum Physics · Physics 2025-04-21 Guannan Zhang , Jiamin Xu , Ming Li , Shuqian Shen , Lei Li , Shao-ming Fei

Self-testing enables the characterization of quantum systems with minimal assumptions on their internal working as such it represents the strongest form of certification for quantum systems. In the existing self-testing literature,…

Quantum Physics · Physics 2024-05-14 Ranendu Adhikary

Alice and Bob each have half of a pair of entangled qubits. Bob measures his half and then passes his qubit to a second Bob who measures again and so on. The goal is to maximize the number of Bobs that can have an expected violation of the…

Quantum Physics · Physics 2020-09-02 Peter J. Brown , Roger Colbeck

For every $d \geq 2$, we present a generalization of the CHSH inequality with the property that maximal violation self-tests the maximally entangled state of local dimension $d$. This is the first example of a family of inequalities with…

Quantum Physics · Physics 2019-04-05 Andrea Coladangelo

Characterizing large quantum systems with minimal assumptions is a central challenge in quantum information science. Self-testing provides the strongest form of certification by identifying the underlying quantum state solely from observed…

Quantum Physics · Physics 2026-05-15 Jinchang Liu , Elias X. Huber , Zhenyu Du , Xingjian Zhang , Xiongfeng Ma

We study the nonlocality of arbitrary dimensional bipartite quantum states. By computing the maximal violation of a set of multi-setting Bell inequalities, an analytical and computable lower bound has been derived for general two-qubit…

Quantum Physics · Physics 2015-09-04 Ming Li , Tinggui Zhang , Bobo Hua , Shao-Ming Fei , Xianqing Li-Jost