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Related papers: Leggett-Garg Inequalities, Pilot Waves and Context…

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The violation of J. Bell's inequality with two entangled and spatially separated quantum two- level systems (TLS) is often considered as the most prominent demonstration that nature does not obey ?local realism?. Under different but related…

The Leggett-Garg inequality (LGI) serves as a criterion to determine the adherence of macroscopic system dynamics to macrorealism, as introduced by Leggett and Garg. A violation of this inequality implies either the absence of a realistic…

Quantum Physics · Physics 2025-02-24 Tsubasa Sakamoto , Ryosuke Yoshii , Shunji Tsuchiya

We propose a generalisation of the Leggett-Garg conditions for macrorealistic behaviour. Our proposal relies on relaxing the postulate of non-invasive measurability with that of retrievability of information. This leads to a strictly…

Quantum Physics · Physics 2026-03-03 Roope Uola , Erkka Haapasalo , Juha-Pekka Pellonpää , Tom Kuusela

Leggett-Garg inequalities are an important milestone in our quest to bridge the classical-quantum divide. An experimental investigation of these inequalities requires the so called \emph{non-invasive measurements}(NIM). It has become…

Quantum Physics · Physics 2015-09-18 N. D. Hari Dass

The widespread claim that violations of Bell inequalities establish the nonlocality of nature is critically reexamined. It is argued that this conclusion is not logically compelled by either the Einstein-Podolsky-Rosen (EPR) argument or…

Quantum Physics · Physics 2026-05-05 Partha Ghose

We discuss a scheme for macrorealistic theories of the Leggett-Garg form [A. J. Leggett and A. Garg, Phys. Rev. Lett. 54, 857 (1985)]. Our scheme is based on a hybrid optomechanical system. It seems reasonable to test these inequalities…

Quantum Physics · Physics 2020-03-13 Marta Maria Marchese , Hannah McAleese , Angelo Bassi , Mauro Paternostro

Contextuality is a feature of quantum correlations. It is crucial from a foundational perspective as a nonclassical phenomenon, and from an applied perspective as a resource for quantum advantage. It is commonly defined in terms of hidden…

Quantum theory predicts and experiments confirm that nature can produce correlations between distant events that are nonlocal in the sense of violating a Bell inequality. Nevertheless, Bell's strong sentence {\it Correlations cry out for…

Some new temporal Bell inequalities are deduced under joint realism assumption, using some perfect correlation property. No locality condition is needed. When the measured system is a macroscopic system, joint realism assumption substitutes…

Quantum Physics · Physics 2007-05-23 Ramon Lapiedra

We investigate the three-term Leggett-Garg inequality (LGI) for a two-level quantum system undergoing parity-time (PT ) symmetric dynamics governed by a non-Hermitian Hamiltonian, when a sequence of dichotomic projective measurements are…

Quantum Physics · Physics 2021-03-24 H. S. Karthik , Akshata Shenoy Hejamadi , A. R. Usha Devi

This short article concentrates on the conceptual aspects of the violation of Bell inequalities, and acts as a map to the 265 cited references. The article outlines (a) relevant characteristics of quantum mechanics, such as statistical…

Quantum Physics · Physics 2021-06-29 Brian Drummond

The correlations between successive measurements of a quantum system can violate a family of Leggett-Garg Inequalities (LGIs) that are analogous to the violation of Bell's inequalities of measurements performed on spatially separated…

High Energy Physics - Phenomenology · Physics 2026-01-30 Kathrine Mørch Groth , Johann Ioannou-Nikolaides , D. Jason Koskinen , Markus Ahlers

We address the basic meaning of apparent contradictions of quantum theory and probability frameworks as expressed by Bell's inequalities. We show that these contradictions have their origin in the incomplete considerations of the premisses…

Quantum Physics · Physics 2011-05-31 Hans De Raedt , Karl Hess , Kristel Michielsen

We investigate the nonclassicality of an open quantum system using Leggett-Garg inequality (LGI) which test the correlations of a single system measured at different times. Violation of LGI implies nonclassical behavior of the open system.…

Quantum Physics · Physics 2017-04-11 Md. Manirul Ali , Po-Wen Chen

We consider typical experiments that use Bell-inequalities to test local-realist theories of quantum mechanics and gain insight into how certain results can be obtained. We see that results against local-realism arise from some `quantum…

Quantum Physics · Physics 2017-08-29 Dale Hodgson

We investigate the Leggett-Garg inequalities (LGIs) for a boson system whose observables are given by deforming the Pegg-Barnett phase operators. We consider two observables and show that the quantum Fourier transform is useful in the…

Quantum Physics · Physics 2023-02-09 Hiroo Azuma , William J. Munro , Kae Nemoto

In the first part of this presentation (sections 2 to 6), I show that Bell's Inequalities provide a quantitative criterion to test "reasonable" Supplementary Parameters Theories versus Quantum Mechanics. Following Bell, I first explain the…

Quantum Physics · Physics 2007-05-23 Alain Aspect

We study the macroscopic realism (macrorealism) through the two- and three-time Leggett-Garg inequalities (LGIs) in a two interacting qubits system. The two qubits are coupled either with two bosonic (thermal or photonic) baths or fermionic…

Quantum Physics · Physics 2020-05-26 Kun Zhang , Wei Wu , Jin Wang

We report an experimental study of recently formulated entropic Leggett-Garg inequality (ELGI) by Usha Devi et al. (arXiv: 1208.4491v2 (2012)). This inequality places a bound on the statistical measurement outcomes of dynamical observables…

Quantum Physics · Physics 2013-05-08 Hemant Katiyar , Abhishek Shukla , Rama Koteswara Rao , T. S. Mahesh

Investigation the boundary between quantum mechanical description and classical realistic view is of fundamental importance. The Leggett-Garg inequality provides a criterion to distinguish between quantum systems and classical systems, and…

Quantum Physics · Physics 2022-05-04 Maimaitiyiming Tusun , Wei Cheng , Zihua Chai , Yang Wu , Ya Wang , Xing Rong , Jiangfeng Du