Article
Astronomy & Astrophysics
Patrick Huber, Hisakazu Minakata, Djordje Minic, Rebekah Pestes, Tatsu Takeuchi
Summary: Neutrino oscillations at JUNO provide a unique opportunity to study Sorkin's triple path interference. The research finds that the bounds on triple path interference by neutrinos are comparable to those from electromagnetic probes, but the neutrino probe is more direct and independent of any boundary conditions compared to electromagnetic probes.
Article
Multidisciplinary Sciences
Pengfei Wang, Junhua Zhang, Chun-Yang Luan, Mark Um, Ye Wang, Mu Qiao, Tian Xie, Jing-Ning Zhang, Adan Cabello, Kihwan Kim
Summary: In this study, the observation of quantum contextuality without detection, sharpness, and compatibility loopholes is reported. By adopting a hybrid two-ion system and highly efficient fluorescence measurements, the detection and sharpness loopholes are closed. The compatibility loophole is closed by targeting correlations between two different ions. The experimental results violate the bound for the most adversarial noncontextual models and provide a way to certify quantum systems.
Article
Optics
Lihua Yang, Xiaofei Qi, Jinchuan Hou
Summary: In this work, the nonlocality of (2(n) - 1)-partite tree-tensor networks used in quantum communications is considered. Bell-type inequalities are derived which are satisfied by all (2(n) - 2)-local correlations and all local correlations, showcasing the maximal quantum violations of these inequalities and their robustness to noise in these tree networks.
Article
Optics
Jonas Kitzinger, Xin Meng, Matteo Fadel, Valentin Ivannikov, Kae Nemoto, William J. Munro, Tim Byrnes
Summary: This study proposes and analyzes a protocol for observing a violation of the CHSH Bell inequality using BECs, demonstrating the potential for violations and investigating the effects of losses and imperfect detection efficiency. The observed violations were found to be robust against noise, highlighting the feasibility of using this approach for testing Bell inequalities.
Article
Multidisciplinary Sciences
Emanuele Polino, Davide Poderini, Giovanni Rodari, Iris Agresti, Alessia Suprano, Gonzalo Carvacho, Elie Wolfe, Askery Canabarro, George Moreno, Giorgio Milani, Robert W. Spekkens, Rafael Chaves, Fabio Sciarrino
Summary: The authors realize a photonic experiment to demonstrate a triangle causal structure, which violates classical predictions without external inputs. The violation of Bell inequalities can only be explained by modeling causal dependencies as intrinsically quantum. There are also other causal structures beyond Bell that can witness nonclassicality, some of which do not require external inputs.
NATURE COMMUNICATIONS
(2023)
Article
Multidisciplinary Sciences
Mohsen Ruzbehani
Summary: This paper presents a simple model using Malus' law and quantum steering concept to simulate phenomena and show that it agrees with predictions of quantum mechanics. The model can be applied to simulate difficult to evaluate effects such as detector deficiencies and different photon values, providing insights into the behavior of these systems.
SCIENTIFIC REPORTS
(2021)
Article
Physics, Particles & Fields
Bhavna Yadav, Trisha Sarkar, Khushboo Dixit, Ashutosh Kumar Alok
Summary: Non-local correlations in entangled systems can be effectively captured by measures like Bell's inequality violation, but in neutrino systems, the non-local advantage of quantum coherence (NAQC) is found to be a stronger measure. The effects of non standard interaction (NSI) on these measures, including Bell's inequality violation and NAQC, have been analyzed for various experimental setups, showing differences in sensitivity to NSI between the two measures.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Optics
Sonia Mazzucchi, Nicolo Leone, Stefano Azzini, Lorenzo Pavesi, Valter Moretti
Summary: This paper addresses the issue of nonidealities in experimental devices affecting single-particle entanglement experiments by quantitatively analyzing the behavior of realistic devices in photon SPE experiments. The analysis allows for a semi-device-independent randomness certification of realistic quantum random-number generators based on SPE states of photons. Additionally, the paper proposes an unbiased estimator for quantum transition probabilities based on experimental data.
Article
Quantum Science & Technology
Kaushik Joarder, Debashis Saha, Dipankar Home, Urbasi Sinha
Summary: In this experiment, conducted using a sophisticated single-photon experimental setup, we comprehensively addressed the crucial loopholes in macrorealism experiments and successfully demonstrated clear violations of the Leggett-Garg inequality (LGI) and Wigner's form of the Leggett-Garg inequality (WLGI). The experimental results are consistent with quantum mechanical predictions and confirm the noninvasiveness of our implemented negative result measurement.
Article
Optics
Kornikar Sen, Chirag Srivastava, Shiladitya Mal, Aditi Sen(De), Ujjwal Sen
Summary: There exists an entanglement witness for every entangled state where negativity of the expectation value guarantees entanglement, with measurement-device-independent entanglement witnesses introduced to remove imperfections. Through analysis, upper bounds and threshold values can be determined for guaranteeing entanglement in nonideal detector efficiency scenarios.
Article
Quantum Science & Technology
Bradley Longstaff, Jonatan Bohr Brask
Summary: We investigate nonlocal quantum correlations arising between multiple two-level impurity atoms coupled to an ultracold bosonic gas. Genuine multipartite nonlocality is observed in a system of three impurities, and non-Markovian effects and the persistence of coherences in the impurity subsystem are crucial for preventing complete loss of nonlocality and allowing for nonlocal correlations to be generated and maintained for extended periods of time.
Article
Physics, Multidisciplinary
Artur Niezgoda, Jan Chwedenczuk
Summary: The study demonstrates that many-body nonlocality witnessed by a broad family of Bell inequalities is a resource for ultraprecise metrology, allowing for tracking sensitivity growth with extending nonlocality. Near a quantum critical point, rapid sensitivity increase is accompanied by the emergence of many-body Bell nonlocality, providing a systematic study of highly quantum phenomena in complex systems. This work extends the understanding of the beneficial role played by fundamental nonclassical effects in implementations of quantum-enhanced protocols.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Xiao-Min Hu, Chao Zhang, Bi-Heng Liu, Yu Guo, Wen-Bo Xing, Cen-Xiao Huang, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo
Summary: Violation of Bell's inequalities demonstrates a strong conflict between quantum mechanics and local realism. Loophole-free Bell tests not only enhance understanding of quantum mechanics, but also serve as important foundations for device-independent tasks in quantum information. High-dimensional quantum systems have significant advantages over qubits in closing the detection loophole.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Johannes Seiler, Thomas Strohm, Wolfgang P. Schleich
Summary: The study reveals that maximizing the correlation measure in the Clauser-Horne-Shimony-Holt inequality for pure and mixed states can be simplified to maximizing the perimeter of a parallelogram enclosed by an ellipse characterized by the entanglement in the bipartite system. This geometrical description is applicable to nonmaximally entangled states, and the corresponding optimal measurements have been identified.
Article
Physics, Particles & Fields
Shu-Min Wu, Hao-Sheng Zeng
Summary: This paper studies the genuine tripartite nonlocality (GTN) and genuine tripartite entanglement (GTE) of Dirac fields in the background of a Schwarzschild black hole. The results show that Hawking radiation degrades both the physically accessible GTN and GTE, with the former experiencing sudden death at a critical Hawking temperature and the latter approaching a non-zero asymptotic value at infinite Hawking temperature. It is also found that Hawking effect can generate physically inaccessible GTE for fermion fields in curved spacetime, but not physically inaccessible GTN. Additionally, monogamy relations between physically accessible GTE and physically inaccessible GTE are discovered.
EUROPEAN PHYSICAL JOURNAL C
(2022)
Article
Physics, Multidisciplinary
Fabian Pokorny, Chi Zhang, Gerard Higgins, Adan Cabello, Matthias Kleinmann, Markus Hennrich
PHYSICAL REVIEW LETTERS
(2020)
Article
Physics, Applied
Giulio Foletto, Luca Calderaro, Armin Tavakoli, Matteo Schiavon, Francesco Picciariello, Adan Cabello, Paolo Villoresi, Giuseppe Vallone
PHYSICAL REVIEW APPLIED
(2020)
Article
Physics, Multidisciplinary
Adan Cabello
Summary: Bell non-locality and KS contextuality are logically independent concepts in quantum theory, but there are one-to-one and partial connections between the two in certain scenarios. The mapping introduced in the work shows how quantum Bell non-local behavior can be transformed into KS contextual behavior, and vice versa, for some situations. This provides insights into the relationships and conversions between these concepts in quantum theory.
FOUNDATIONS OF PHYSICS
(2021)
Article
Physics, Multidisciplinary
Adan Cabello
Summary: The paper introduces a general method to convert any form of quantum contextuality into a quantum violation of a bipartite Bell inequality. As an example, the method is applied to the Klyachko-Can-Binicioglu-Shumovsky inequality.
PHYSICAL REVIEW LETTERS
(2021)
Article
Physics, Multidisciplinary
Stefan Trandafir, Petr Lisonek, Adan Cabello
Summary: Magic sets of observables are fundamental tools for investigating the interface between classical and quantum physics. This study answers two open questions regarding magic sets and provides an efficient algorithm for determining if a hypergraph can accommodate a magic set.
PHYSICAL REVIEW LETTERS
(2022)
Article
Physics, Multidisciplinary
Nikolai Miklin, Anubhav Chaturvedi, Mohamed Bourennane, Marcin Pawlowski, Adan Cabello
Summary: We address the problem of closing the detection efficiency loophole in Bell experiments and propose a general method for reducing the critical detection efficiency of any Bell inequality. This is accomplished by entangling two particles in multiple orthogonal subspaces and conducting multiple Bell tests. The proposed method closes the simultaneous measurement loophole by introducing penalized N-product Bell inequalities.
PHYSICAL REVIEW LETTERS
(2022)
Review
Physics, Multidisciplinary
Costantino Budroni, Adan Cabello, Otfried Guehne, Matthias Kleinmann, Jan-Ake Larsson
Summary: This article introduces the Kochen-Specker theorem, a central result in the foundations of quantum mechanics, and its conflict with classical models. It reviews several proofs of the theorem and different notions of contextuality, and discusses the connections between contextuality and nonlocality or graph theory. Finally, it reviews the applications of contextuality in quantum information processing.
REVIEWS OF MODERN PHYSICS
(2022)
Article
Physics, Multidisciplinary
Zheng-Hao Liu, Hui-Xian Meng, Zhen-Peng Xu, Jie Zhou, Jing-Ling Chen, Jin-Shi Xu, Chuan-Feng Li, Guang-Can Guo, Adan Cabello
Summary: We address the lack of robustness in existing examples of contextuality in high-dimensional systems by identifying a family of noncontextuality inequalities whose maximum quantum violation grows with the dimension of the system. We show the practicality of this result by presenting an experimental test of contextuality in a seven-dimensional system, where we report a violation of 68.7 standard deviations. Our findings advance the investigation of high-dimensional contextuality and its role in quantum computation.
PHYSICAL REVIEW LETTERS
(2023)
Article
Physics, Multidisciplinary
Junior R. Gonzales-Ureta, Ana Predojevic, Adan Cabello
Summary: We have discovered a new type of Bell inequalities that are optimal for state-independent contextuality (SI-C) sets, allowing for robust nonlocality in the face of noise. This opens up possibilities for studying the applications of nonlocality and contextuality in experiments.
PHYSICAL REVIEW RESEARCH
(2023)
Article
Quantum Science & Technology
Kishor Bharti, Maharshi Ray, Zhen-Peng Xu, Masahito Hayashi, Leong-Chuan Kwek, Adan Cabello
Summary: This study addresses the problem of self-testing quantum correlations using tools from graph theory. It is found that the set of quantum correlations, BQ, is strictly contained in a set associated with a graph, 0(G), which is easier to characterize. When the optimum values of BQ and 0(G) coincide, self-testing can be demonstrated by proving self-testability with 0(G). This approach also connects self-testing to open problems in discrete mathematics.
Article
Optics
Ali Asadian, Adan Cabello
Summary: This article introduces a scheme to address the problem of producing contextual correlations in sequences of measurements on single quantum systems. By encoding quantum information in indistinguishable bosons in multiple modes and performing ideal measurements with auxiliary qubits, the authors were able to realize sequential quantum measurements on high-dimensional quantum systems and generate contextuality that cannot be simulated by classical light.
Article
Multidisciplinary Sciences
Pengfei Wang, Junhua Zhang, Chun-Yang Luan, Mark Um, Ye Wang, Mu Qiao, Tian Xie, Jing-Ning Zhang, Adan Cabello, Kihwan Kim
Summary: In this study, the observation of quantum contextuality without detection, sharpness, and compatibility loopholes is reported. By adopting a hybrid two-ion system and highly efficient fluorescence measurements, the detection and sharpness loopholes are closed. The compatibility loophole is closed by targeting correlations between two different ions. The experimental results violate the bound for the most adversarial noncontextual models and provide a way to certify quantum systems.
Article
Optics
Junior R. Gonzales-Ureta, Ana Predojevic, Adan Cabello
Summary: The paper discusses two DI-QKD protocols that rely on Bell inequalities with more than two inputs and two outputs. It shows that, for maximally entangled states and perfect visibility, a protocol based on a Bell inequality with three inputs and four outputs requires slightly lower detection efficiency than those based on Bell inequalities with two inputs and two outputs.
Article
Physics, Multidisciplinary
Giulio Chiribella, Adan Cabello, Matthias Kleinmann, Markus P. Mueller
PHYSICAL REVIEW RESEARCH
(2020)
Article
Optics
Ari Patrick, Adan Cabello
