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Related papers: Inequivalent Leggett-Garg inequalities

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I study several aspects of tests of macrorealism (MR), which for a given data set serves to give a quantitative signal of the presence of a specific notion of non-classical behaviour. The insufficiency of classical understanding underpins…

Quantum Physics · Physics 2024-02-27 Clement Mawby

Macroscopic realism is a set of assumptions about how we experience the world at a classical level. While the Leggett-Garg inequalities are temporal correlations that are violated by quantum systems not obeying such macrorealism, the…

Quantum Physics · Physics 2025-12-23 Manish Ramchander , Arul Lakshminarayan

This study investigates the emergence of macroscopic classical behavior from quantum foundations via the entropic Leggett--Garg inequality. We introduce a geometric framework for deriving entropic Leggett--Garg inequalities with…

Quantum Physics · Physics 2025-12-01 Qi-Hong Cai , Xue-Hao Yu , Ma-Cheng Yang , Ao-Xiang Liu , Cong-Feng Qiao

Leggett Garg inequalities (LGIs) test the incompatibility between the notion of macrorealism and quantum mechanics. For unitary dynamics, the optimal quantum violation of an LGI is constrained by the L\"uders bound. However, the LGIs does…

Quantum Physics · Physics 2022-05-18 Asmita Kumari , A. K. Pan

Leggett-Garg inequalities (LGI) are constrains on certain combinations of temporal correlations obtained by measuring one and the same system at two different instants of time. The usual derivations of LGI assume \emph {macroscopic realism…

Quantum Physics · Physics 2014-06-24 Shiladitya Mal , Manik Banik , Sujit K Choudhary

According to the world view of macrorealism, the properties of a given system exist prior to and independent of measurement, which is incompatible with quantum mechanics. Leggett and Garg put forward a practical criterion capable of…

Quantum Physics · Physics 2018-06-27 Eugenio Roldán , Johannes Kofler , Carlos Navarrete-Benlloch

Violation of Leggett-Garg inequalities allows proof of the incompatibility between quantum mechanics and the combined premises (called macrorealism) of macroscopic realism (MR) and non-invasive measurability (NIM). Arguments can be given…

Quantum Physics · Physics 2024-12-03 Jesse Fulton , M. Thenabadu , Run Yan Teh , M. D. Reid

The Bell-type (spatial), Kochen-Specker (contextuality) or Leggett-Garg (temporal) inequalities are based on classically plausible but otherwise quite distinct assumptions. For any of these inequalities, satisfaction is equivalent to a…

Quantum Physics · Physics 2014-02-20 Siddhartha Das , S. Aravinda , R. Srikanth , Dipankar Home

Violation of the Leggett-Garg inequality (LGI) implies quantum phenomena. In this light we establish that the Moreva \textit{et al.} \cite{moreva} experiment demonstrating the Page-Wootter's mechanism \cite{wootters} falls in the quantum…

Quantum Physics · Physics 2017-02-01 D. Gangopadhyay , A. Sinha Roy

Temporal Bell inequalities, or Leggett-Garg Inequalities (LGI), are studied for continuous-variable systems placed in a squeezed state. The importance of those systems lies in their broad applicability which allows the description of many…

Quantum Physics · Physics 2021-07-19 Jerome Martin , Vincent Vennin

Macro-realism is a fundamental feature of classical world that contradicts with the quantum theory. An elegant method of testing macrorealism is to apply the Leggett-Garg inequality (LGI), but the non-invasivity of measurement is…

Quantum Physics · Physics 2023-02-20 Hui Wang , Shuang Wang , Cong-Feng Qiao

Quantum mechanics presents peculiar properties that, on the one hand, have been the subject of several theoretical and experimental studies about its very foundations and, on the other hand, provide tools for developing new technologies,…

We use two different approaches to derive multipartite Leggett-type inequalities, which are generalizations of the two-qubit Leggett-type inequality obtained in [Nature Phys. \textbf{4}, 681 (2008)]. The first approach is based on the…

Quantum Physics · Physics 2011-11-18 Dong-Ling Deng , Chunfeng Wu , Jing-Ling Chen , C. H. Oh

In this study, we determine a violation of the Leggett-Garg inequalities due to gravitational interaction in a hybrid system consisting of a harmonic oscillator and a spatially localized superposed particle. The violation of the…

Quantum Physics · Physics 2022-08-23 Akira Matsumura , Yasusada Nambu , Kazuhiro Yamamoto

We show how to apply the Leggett-Garg inequality to opto-electro-mechanical systems near their quantum ground state. We find that by using a dichotomic quantum non-demolition measurement (via, e.g., an additional circuit-QED measurement…

Quantum Physics · Physics 2012-09-17 Neill Lambert , Robert Johansson , Franco Nori

Leggett-Garg's inequalities predict sharp bounds for some classical correlation functions that address the quantum or classical nature of real-time evolutions. We experimentally observe the violations of these bounds on single- and…

Quantum Physics · Physics 2022-04-06 Alessandro Santini , Vittorio Vitale

In 1985, Leggett and Garg (1985 Phys. Rev. Lett. 54 857) proposed a Bell-like inequality to test (in)compatibility between two fundamental concepts of quantum mechanics. The first concept is 'macroscopic realism', which is the quality of a…

Quantum Physics · Physics 2011-05-13 A M Souza , I S Oliveira , R S Sarthour

Quantum non-demolition measurements define a non-invasive protocol to extract information from a quantum system that we aim to monitor. They exploit an additional quantum system that is sequentially coupled to the system. Eventually, by…

Quantum Physics · Physics 2025-06-16 Paolo Solinas , Stefano Gherardini

By weakly measuring the polarization of a photon between two strong polarization measurements, we experimentally investigate the correlation between the appearance of anomalous values in quantum weak measurements, and the violation of…

Quantum Physics · Physics 2011-03-30 M. E. Goggin , M. P. Almeida , M. Barbieri , B. P. Lanyon , J. L. O'Brien , A. G. White , G. J. Pryde

Nonclassicality of temporal correlations pertaining to noncommutative sequential measurements is defined through the violation of macrorealistic inequalities, known as Leggett-Garg inequalities (LGI). We investigate the energy cost of the…

Quantum Physics · Physics 2018-09-11 Titas Chanda , Tamoghna Das , Shiladitya Mal , Aditi Sen De , Ujjwal Sen