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Three flavoured neutrino oscillations are investigated in the light of the Leggett-Garg inequality. The outline of an experimental proposal is suggested whereby the findings of this investigation may be verified. The results obtained are:…

Quantum Physics · Physics 2017-05-24 Debashis Gangopadhyay , Animesh Sinha Roy

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

Ambiguous measurements do not reveal complete information about the system under test. Their quantum-mechanical counterparts are semi-weak (or in the limit, weak-) measurements and here we discuss their role in tests of the Leggett-Garg…

Quantum Physics · Physics 2017-10-11 Clive Emary

We realise a quantum three-level system with photons distributed among three different spatial and polarization modes. Ambiguous measurement of the state of the qutrit are realised by blocking one out for the three modes at any one time.…

Quantum Physics · Physics 2018-02-14 Kunkun Wang , Clive Emary , Mengyan Xu , Xiang Zhan , Zhihao Bian , Lei Xiao , Peng Xue

We prove that a violation of a Leggett-Garg inequality for bounded observables in stationary pure states and thermal states yields a rigorous lower bound on the quantum Fisher information. This turns a qualitative foundations test of…

Quantum Physics · Physics 2026-04-14 Nick Abboud , Yuntao Guan , Barry Bradlyn , Jorge Noronha

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

The Leggett-Garg (LG) inequalities were proposed in order to assess whether sets of pairs of sequential measurements on a single quantum system can be consistent with an underlying notion of macrorealism. Here, the LG inequalities are…

Quantum Physics · Physics 2016-03-02 J. J. Halliwell

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…

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

Leggett-Garg Inequality~(LGI) is a time analogue of Bell's inequality that concerns measurements performed on a system at different times. Violation to LGI indicates quantum coherence. We present a Leggett-Garg-type inequality compatible…

Quantum Physics · Physics 2022-02-15 Xing-Zhi Wang , Bo-Qiang Ma

In this paper, we study the two-time Leggett-Garg (LG) inequalities of a quantum optical model that appears in the Josephson-junction quantum bit (qubit) interacting with an external magnetic flux. This model is a natural extension of an…

Quantum Physics · Physics 2026-01-19 Hiroo Azuma

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…

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,…

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

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

Quantum mechanics has always proven emphatically as one of the main cornerstones in all of science since its inception. Initially, it has also faced many skeptics from many scientific proponents of its complete description of reality.…

High Energy Physics - Phenomenology · Physics 2024-10-30 Kiran Sharma , Aryabrat Mahapatra , Prasanta K. Panigrahi , Sudhanwa Patra

The present work is devoted to the characterization of the Leggett-Garg inequality for three-flavoured neutrino oscillations in presence of both matter and Charge-Conjugation and Parity violating (CP) effects. This study complements and…

High Energy Physics - Phenomenology · Physics 2019-05-08 Javid Naikoo , Ashutosh Kumar Alok , Subhashish Banerjee , S. Uma Sankar

Entropic Leggett-Garg inequality is studied in systems like neutrinos in the context of two and three flavor neutrino oscillations and in neutral $B_d$, $B_s$ and $K$ mesons. The neutrino dynamics is described with the matter effect taken…

High Energy Physics - Phenomenology · Physics 2018-08-02 Javid Naikoo , Subhashish Banerjee

As is well known, the macroscopic realism and the noninvasive measurability together lead to Leggett-Garg inequalities violated by quantum mechanics. We consider tests of the Leggett-Garg type with use of the $q$-entropies. For all…

Quantum Physics · Physics 2014-11-11 Alexey E. Rastegin

The Leggett-Garg inequalities are a set of inequalities obeyed by classical systems but violated in quantum theory. Their violation has been taken as evidence that quantum theory lacks a `realistic' formulation. However in addition to…

Quantum Physics · Physics 2013-10-09 JM Yearsley