English
Related papers

Related papers: Leggett-Garg inequalities for multitime processes

200 papers

Macroscopic realism (MR) is the view that a system may possess definite properties at any time independent of past or future measurements, and may be tested experimentally using the Leggett-Garg inequalities (LGIs). In this work we advance…

The Leggett-Garg inequality (LGI) is a temporal analogue of Bell's inequality and provides a quantitative test of the nonclassicality of a system through its violation. We analytically investigate the violation of the LGI in the context of…

General Relativity and Quantum Cosmology · Physics 2026-01-29 Kimihiro Nomura , Akira Taniguchi , Kazushige Ueda

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

Despite the great success of quantum mechanics, questions regarding its application still exist and the boundary between quantum and classical mechanics remains unclear. Based on the philosophical assumptions of macrorealism and noninvasive…

Quantum Physics · Physics 2012-04-24 Jin-Shi Xu , Chuan-Feng Li , Xu-Bo Zou , Guang-Can Guo

Quantum theory contravenes classical macrorealism by allowing a system to be in a superposition of two or more physically distinct states, producing physical consequences radically different from that of classical physics. We show that a…

Quantum Physics · Physics 2026-02-03 Arijit Chatterjee , H. S. Karthik , T. S. Mahesh , A. R. Usha Devi

We demonstrate the first violation of the Leggett-Garg inequality and time-order noninvariance on public quantum computers using genuine noninvasive measurements. By gathering sufficiently large statistics, we have been able to violate…

We investigate the relation between a refined version of Leggett and Garg conditions for macrorealism, namely the no-signaling-in-time (NSIT) conditions, and the quantum mechanical notion of nondisturbance between measurements. We show that…

Quantum Physics · Physics 2019-11-05 Roope Uola , Giuseppe Vitagliano , Costantino Budroni

We propose a new Wigner inequality suitable for test of the hypothesis of realism. We show that this inequality is not identical neither to the well-known Wigner inequality nor to the Leggett-Garg inequality in Wigner form. The obtained…

Quantum Physics · Physics 2019-12-18 N. Nikitin , K. Toms

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

The Leggett-Garg inequality attempts to classify experimental outcomes as arising from one of two possible classes of physical theories: those described by macrorealism (which obey our intuition about how the macroscopic classical world…

Quantum Physics · Physics 2020-12-22 Huan-Yu Ku , Neill Lambert , Fong-Ruei Jhan , Clive Emary , Yueh-Nan Chen , Franco Nori

An implementation of weak values is investigated in solid-state qubits. We demonstrate that a weak value can be non-classical if and only if a Leggett-Garg inequality can also be violated. Generalized weak values are described, where…

Mesoscale and Nanoscale Physics · Physics 2008-01-16 Nathan S. Williams , Andrew N. Jordan

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

Wigner's form of the local realist inequality is used to derive its temporal version for an oscillating two-level system involving two-time joint probabilities. Such an inequality may be regarded as a novel form of the Leggett-Garg…

Quantum Physics · Physics 2015-03-24 Debashis Saha , Shiladitya Mal , Prasanta K. Panigrahi , Dipankar Home

The connection between the Leggett-Garg inequality and optimal scenarios from the point of view of quantum metrology is investigated for perfect and noisy general dichotomic measurements. In this context, we show that the Fisher information…

The Leggett-Garg (LG) test of macroscopic realism involves a series of dichotomic non-invasive measurements that are used to calculate a function which has a fixed upper bound for a macrorealistic system and a larger upper bound for a…

Quantum Physics · Physics 2017-02-23 Hemant Katiyar , Aharon Brodutch , Dawei Lu , Raymond Laflamme

We construct quantifiable generalisations of Leggett-Garg tests for macro/ mesoscopic realism and noninvasive measurability that apply when not all outcomes of measurement can be identified as arising from one of two macroscopically…

Quantum Physics · Physics 2024-12-13 L. Rosales-Zárate , B. Opanchuk , Q. Y. He , M. D. Reid

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

A recent paper by Souza, Oliveira and Sarthour (SOS) reports the experimental violation of a Leggett-Garg inequality (sometimes referred to as a temporal Bell inequality). The inequality tests for quantum mechanical superposition: if the…

Quantum Physics · Physics 2012-07-13 George C. Knee , Erik M. Gauger , G. Andrew D. Briggs , Simon C. Benjamin

The Leggett-Garg inequality, an analogue of Bell's inequality involving correlations of measurements on a system at different times, stands as one of the hallmark tests of quantum mechanics against classical predictions. The phenomenon of…

Quantum Physics · Physics 2016-07-29 J. A. Formaggio , D. I. Kaiser , M. M. Murskyj , T. E. Weiss

Leggett Garg inequalities (LGIs) provide an elegant way for probing the incompatibility between the notion of macrorealism and quantum mechanics. For unitary dynamics, the optimal quantum violation of a LGI is constrained by the L\"uders…

Quantum Physics · Physics 2022-03-23 Asmita Kumari , A. K. Pan
‹ Prev 1 3 4 5 6 7 10 Next ›