Article
Multidisciplinary Sciences
Francesca Fabiana Settembrini, Frieder Lindel, Alexa Marina Herter, Stefan Yoshi Buhmann, Jerome Faist
Summary: This research demonstrates the correlation between quantum vacuum electric fields in regions outside the light-cone. According to quantum field theory, empty space is not truly empty, but filled with fluctuations known as quantum-vacuum fluctuations. These fluctuations can be observed through various phenomena. The experimental results show the existence of vacuum field correlations between non-causally connected space-time points.
NATURE COMMUNICATIONS
(2022)
Article
Physics, Multidisciplinary
Da Zhang, David Barral, Yanpeng Zhang, Min Xiao, Kamel Bencheikh
Summary: In this study, a set of sufficient and necessary conditions for separability of the broad family of spontaneously generated three-mode non-Gaussian states is proposed. State-of-the-art conditions for genuine tripartite non-Gaussian entanglement are further derived. Applying these criteria to triple-photon states reveals that they are fully inseparable and genuinely entangled in moments of order 3n. These results establish a systematic framework for characterizing the entanglement of triple-photon states and thus foster their application in quantum information protocols.
PHYSICAL REVIEW LETTERS
(2023)
Article
Optics
Dong -Dong Dong, Geng-Biao Wei, Xue-Ke Song, Dong Wang, Liu Ye
Summary: In this paper, a unified framework for interpreting the interconversions among coherence and different quantum correlations in tripartite systems is proposed. Results include the exact relation between the generalized geometric measure and the genuinely multipartite concurrence for tripartite entanglement states, the trade-off relation between the first-order coherence and the genuine tripartite entanglement, and the trade-off relation between the maximum steering inequality violation and concurrence fill for arbitrary three-qubit states. Additionally, the close relation between the maximum steering inequality violation and the first-order coherence is investigated. The results show that coherence and quantum correlations are intrinsically related and can be converted to one another in the framework of QRTs.
Article
Mathematics, Applied
Tao Wu, Feng An, Xiangyun Gao, Siyao Liu, Xiaotian Sun, Zhigang Wang, Zhen Su, Juergen Kurths
Summary: Correlation analysis is an easy-to-implement method for quantifying the interaction or connectivity between different units. The study finds that the transition from a chaotic-like state to a nonchaotic state occurs with increasing window size in time-varying correlations. This window size-dependent transition is a universal phenomenon and provides a quantitative rule for selecting window sizes.
Article
Geosciences, Multidisciplinary
L. Del Rio Amador, S. Lovejoy
Summary: Granger causality analysis demonstrates that spatial correlations in temperature are not useful for improving predictions based on long memory, indicating that long-term stochastic temperature forecasting is a past value problem. The m-StocSIPS model, despite reproducing teleconnection patterns and El Nino events, does not have causal relationships between different locations useful for long-range predictions. Real-world statistics and teleconnection patterns can be accurately represented through stochastic simulations without causal relationships.
GEOPHYSICAL RESEARCH LETTERS
(2021)
Article
Quantum Science & Technology
Gabriele Lo Monaco, Luca Innocenti, Dario Cilluffo, Dario A. Chisholm, Salvatore Lorenzo, G. Massimo Palma
Summary: Quantum information scrambling (QIS), which is the local non-retrievability of information evolved through dynamic processes, is often quantified using entropic quantities such as the tripartite information. However, this approach has some issues due to its reliance on quantum mutual informations that do not accurately quantify correlations retrievable via measurements, as well as the specific methodology used to compute the tripartite information. By using accessible mutual informations and defining corresponding 'accessible tripartite informations', these issues can be overcome. Our findings lay the groundwork for a deeper understanding of QIS and open up new avenues for further research.
QUANTUM SCIENCE AND TECHNOLOGY
(2023)
Article
Quantum Science & Technology
Atta Ur Rahman, Muhammad Noman, Muhammad Javed, Ming-Xing Luo, Arif Ullah
Summary: The study examines the preservation of quantum coherence and entanglement in three non-interacting qubits subjected to an external fluctuating field with classical Gaussian noise. Different couplings and noise significantly affect quantum correlation and coherence, with the X-G state showing more dominant and robust non-local correlation and coherence under Gaussian noise, making it a valuable resource for transmitting quantum information with reduced loss.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Physics, Multidisciplinary
Huan Cao, Marc-Olivier Renou, Chao Zhang, Gaël Masse, Xavier Coiteux-Roy, Bi-Heng Liu, Yun-Feng Huang, Chuan-Feng Li, Guang-Can Guo, Elie Wolfe
Summary: Quantum theory predicts the existence of genuinely tripartite-entangled states that cannot be obtained from local operations and unlimited shared randomness. Researchers have experimentally verified these tripartite correlations and proposed a new method for falsifying causal theories limited to bipartite nonclassical resources. The validity of this method has been demonstrated through experiments.
PHYSICAL REVIEW LETTERS
(2022)
Article
Optics
Peter Bierhorst
Summary: This paper introduces a rigorous framework for analyzing tripartite correlations that can be simulated by bipartite-only networks. The expected properties of these correlations, such as no-signaling, are confirmed to hold, and the framework is used to derive Bell-inequality-type constraints that can be robustly violated by tripartite quantum systems. Additionally, the framework is used to rederive a version of a constraint previously described in a paper by Chao and Reichardt.
Article
Physics, Multidisciplinary
Nikolai Miklin, Marcin Pawlowski
Summary: The principle of information causality can be used to bound nonlocality in quantum mechanics, simplifying derivations and improvements of Bell inequalities by relying on communication channel capacity rather than concatenation of resources.
PHYSICAL REVIEW LETTERS
(2021)
Article
Optics
Rui Peng, Zhen Yang, Dawei Wang, Ling Zhou
Summary: This paper investigates the quantum entanglement of multiple mechanical oscillators using a multi-tone driving laser. The results demonstrate that three- and four-tone driving can generate and enhance genuine tripartite entanglement, while two-tone driving is not sufficient. The study also provides a method for manipulating the quantum correlation among multiple macroscopic objects.
Article
Optics
Rui Peng, Zhen Yang, Dawei Wang, Ling Zhou
Summary: This paper investigates how to entangle multiple mechanical oscillators using multi-tone driving, and manipulates the mechanical entanglement and EPR steering by modulating the optomechanical coupling. It also demonstrates the monogamous relation of tripartite EPR steering and manipulation of the asymmetry of steering.
Article
Quantum Science & Technology
Wen-jing Li, Liang Tang, Qun Zhang, Ming-qiang Bai
Summary: The paper discusses how obtaining information of a quantum system through quantum measurements can bring disturbances to the system and affect the entanglement between arbitrary bipartite systems. By modeling the measurement process as tripartite systems and defining various information quantities, the relationships between information gain and entanglement in the tripartite systems are explored.
QUANTUM INFORMATION PROCESSING
(2021)
Article
Quantum Science & Technology
Qing-long Tian, You-neng Guo, Xiang-jun Chen, Shi-feng Wang
Summary: Quantum correlations dynamics in a tripartite system are studied in this paper. It is found that the magnetic field, anisotropic coupling coefficient, and DM interaction parameter are effective control parameters for generating and enhancing quantum correlations. Furthermore, the study reveals that the dynamics of tripartite quantum correlations depend on the input configuration of initial states and are more robust against intrinsic decoherence when quantified by D-(3).
QUANTUM INFORMATION PROCESSING
(2023)
Article
Physics, Multidisciplinary
A. -B. A. Mohamed, A. N. Khedr, S. M. Younis
Summary: In this study, the researchers investigate how the dynamics of classical and quantum correlations due to the Unruh effect are manifested in the properties of tripartite entropic uncertainty. They find that, even though quantum correlations vanish at infinite acceleration, the uncertainty about measurement outcomes reaches its minimum. This is because the three-qubit system still contains classical correlations at that stage of acceleration. Furthermore, they observe that the decrease in entropic uncertainty when the measured qubit interacts strongly with the scalar field is due to an increase in classical correlations. They also discover that entropic uncertainty is fully anti-correlated with classical correlations, and minimal uncertainty can be achieved even in the absence of quantum correlations. The researchers successfully define the properties of tripartite entropic uncertainty based on the difference between total correlation and Holevo quantities.
ANNALEN DER PHYSIK
(2023)
Article
Physics, Multidisciplinary
Stella Seah, Stefan Nimmrichter, Valerio Scarani
PHYSICAL REVIEW LETTERS
(2020)
Article
Quantum Science & Technology
J. Kolodynski, A. Mattar, P. Skrzypczyk, E. Woodhead, D. Cavalcanti, K. Banaszek, A. Acin
Article
Quantum Science & Technology
Le Phuc Thinh, Michele Dall'Arno, Valerio Scarani
Article
Multidisciplinary Sciences
Rene Schwonnek, Koon Tong Goh, Ignatius W. Primaatmaja, Ernest Y-Z Tan, Ramona Wolf, Valerio Scarani, Charles C-W Lim
Summary: Device-independent quantum key distribution aims at achieving ultimate quantum-based unconditional security, but current protocols' rates are quite far from anything practical. The authors' protocol narrows this gap by using two randomly chosen key generating bases instead of one.
NATURE COMMUNICATIONS
(2021)
Article
Physics, Multidisciplinary
Tamas Krivachy, Yu Cai, Joseph Bowles, Daniel Cavalcanti, Nicolas Brunner
Summary: The proposed method uses artificial neural networks to solve feasibility semidefinite programs, achieving decent accuracy and orders of magnitude increase in speed compared to traditional solvers for quantum information tasks.
NEW JOURNAL OF PHYSICS
(2021)
Article
Multidisciplinary Sciences
Wei Zhang, Tim van Leent, Kai Redeker, Robert Garthoff, Rene Schwonnek, Florian Fertig, Sebastian Eppelt, Wenjamin Rosenfeld, Valerio Scarani, Charles C-W Lim, Harald Weinfurter
Summary: Device-independent quantum key distribution (DIQKD) is a method that generates secret keys over an untrusted channel using uncharacterized and potentially untrusted devices. This study presents an experimental system that enables DIQKD between two distant users by generating and analyzing event-ready entanglement between two independently trapped single rubidium atoms located 400 meters apart. The results show the system's capability to generate secret keys and pave the way for quantum secure communications in future quantum networks.
Article
Physics, Multidisciplinary
Lin Htoo Zaw, Zakarya Lasmar, Chi-Huan Nguyen, Ko-Wei Tseng, Dzmitry Matsukevichl, Dagomir Kaszlikowski, Valerio Scarani
Summary: This research proposes a probabilistic scheme based on the boson sculpting technique to generate multipartite highly entangled states in trapped ion systems. The effects of decoherence on the fidelity of the generated state are also investigated.
NEW JOURNAL OF PHYSICS
(2022)
Article
Optics
Peter Sidajaya, Wan Cong, Valerio Scarani
Summary: This study proposes a method to address the two fundamental problems of quantum gravity, which are how to prepare a gravity source in a quantum state and how to fight localization by decoherence. The authors suggest using the Zeno effect to freeze the source in the desired state and verifying the successful implementation through scattering a probe.
Article
Optics
Lin Htoo Zaw, Clive Cenxin Aw, Zakarya Lasmar, Valerio Scarani
Summary: Building upon Tsirelson's work, this study presents a series of protocols for detecting the nonclassicality of suitable states in a single quantum system, assuming the measured dynamical observable undergoes a uniform precession. The researchers extend the previous work by Tsirelson to include the case of the harmonic oscillator. Additionally, they apply the protocols to finite-dimensional spins undergoing uniform precession in real space, observing a gap between the classical and quantum expectations for all j 32 (excluding j = 2).
Article
Optics
Baichu Yu, Pooja Jayachandran, Adam Burchardt, Yu Cai, Nicolas Brunner, Valerio Scarani
Summary: This study investigates the properties of absolutely entangled sets (AESs) of pure quantum states, presenting a sufficient condition to detect an AES for two-qubit systems and proving that sets of a certain number of states are AESs with Haar measure 1 for a general bipartition. The research also defines AESs for multipartitions, deriving a lower bound on the number of states in an AES for a given multipartition and providing explicit examples.
Article
Optics
Yu Cai, Baichu Yu, Pooja Jayachandran, Nicolas Brunner, Valerio Scarani, Jean-Daniel Bancal
Summary: This work introduces the concept of absolutely entangled sets of quantum states, where at least one state in the set is entangled for any global basis. A quantitative measure for absolute set entanglement is proposed, with a method based on polynomial optimization to perform convex optimization over unitaries for lower bounding this quantity.
Article
Physics, Fluids & Plasmas
Francesco Buscemi, Valerio Scarani
Summary: The reverse process in the studies of irreversibility in statistical mechanics arises naturally from Bayesian retrodiction, providing a broader scope for fluctuation relations. Previous paradigmatic results, such as Jarzynski's equality, Crooks' fluctuation theorem, and Tasaki's two-measurement fluctuation theorem, are consistent with retrodictive arguments. Various corrections introduced to deal with nonequilibrium steady states or open quantum systems are justified as remnants of Bayesian retrodiction.
Article
Optics
Ignatius William Primaatmaja, Asaph Ho, Valerio Scarani
Summary: The study introduces a toolbox for optimal discrimination of any set of optical modes, using linear and semidefinite programming techniques. The research explores channel-discrimination and source-discrimination scenarios, finding that optimal state for mode discrimination may be a superposition or mixture of at most two number states.
Article
Physics, Multidisciplinary
Clive Aw, Michele Dall'Arno, Valerio Scarani
QUANTUM STUDIES-MATHEMATICS AND FOUNDATIONS
(2020)
Article
Optics
Angeline Shu, Stella Seah, Valerio Scarani