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Related papers: Leggett-Garg inequalities for multitime processes

200 papers

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

We generalize the derivation of Leggett-Garg inequalities to systematically treat a larger class of experimental situations by allowing multi-particle correlations, invasive detection, and ambiguous detector results. Furthermore, we show…

Quantum Physics · Physics 2015-03-18 J. Dressel , C. J. Broadbent , J. C. Howell , A. N. Jordan

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 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

We show that in some cases the coherent state can have a larger violation of the Leggett-Garg inequality (LGI) than the cat state by numerical calculations. To achieve this result, we consider the LGI of the cavity mode weakly coupled to a…

Quantum Physics · Physics 2021-07-13 Hiroo Azuma , Masashi Ban

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

The rise of quantum information theory has lent new relevance to experimental tests for non-classicality, particularly in controversial cases such as adiabatic quantum computing superconducting circuits. The Leggett-Garg inequality is a…

Quantum Physics · Physics 2015-03-13 Mark M. Wilde , Ari Mizel

The Leggett-Garg inequalities impose restrictions on the values taken by some combinations of the two-time correlation functions of observables in order to be explainable by a noninvasive-realist classical model. While in the unitary…

Quantum Physics · Physics 2021-01-19 Javid Naikoo , Subhashish Banerjee , R. Srikanth

We investigate Leggett-Garg temporal inequalities in flavor-mixing processes. We derive an exact flavor-mass uncertainty product and we establish that it is an upper bound to the violation of the inequalities. This finding relates temporal…

Quantum Physics · Physics 2021-12-10 Massimo Blasone , Fabrizio Illuminati , Luciano Petruzziello , Luca Smaldone

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,…

Macrorealism (MR) is the world view that certain quantities may take definite values at all times irrespective of past or future measurements and may be experimentally falsified via the Leggett-Garg (LG) inequalities. We put this world view…

Quantum Physics · Physics 2023-12-06 Clement Mawby , Jonathan Halliwell

The Bell and Leggett-Garg tests offer operational ways to demonstrate that non-classical behavior manifests itself in quantum systems, and experimentalists have implemented these protocols to show that classical worldviews such as local…

Quantum Physics · Physics 2010-09-24 David Avis , Patrick Hayden , Mark M. Wilde

We investigate both analytically and numerically violations of a Leggett-Garg inequality (LGI) for a composite quantum system in contact with two separate reservoirs at different temperatures. Remarkably we find that LGI violations can be…

Mesoscale and Nanoscale Physics · Physics 2015-06-15 Juan C. Castillo , Ferney J. Rodríguez , Luis Quiroga

We formulate entropic Leggett-Garg inequalities, which place constraints on the statistical outcomes of temporal correlations of observables. The information theoretic inequalities are satisfied if macrorealism holds. We show that the…

Quantum Physics · Physics 2013-05-21 A. R. Usha Devi , H. S. Karthik , Sudha , A. K. Rajagopal

In an endeavour to better define the distinction between classical macroscopic and quantum microscopic regimes, the Leggett-Garg inequalities were established as a test of macroscopic-realistic theories, which are commonly thought to be a…

Quantum Physics · Physics 2021-04-14 Hadrien Chevalier , A. J. Paige , Hyukjoon Kwon , M. S. Kim

We investigate how discrete internal degrees of freedom in a quasi-macroscopic system affect the violation of the Leggett--Garg inequality, a test of macroscopic-realism based on temporal correlation functions. As a specific example, we…

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 consider maximal violations of the Leggett-Garg inequality, obtained by maximising over all possible measurement operators, in relation to non-unitary aspects of the system dynamics. We model the action of an environment on a qubit in…

Quantum Physics · Physics 2013-04-22 Clive Emary

The Leggett-Garg inequality (LGI) places a bound for the distinction between quantum systems and classical systems. Despite that the tests of temporal quantum correlations on LGIs have been studied in Hermitian realm, there are still…

Quantum Physics · Physics 2024-06-21 Pengfei Lu , Xinxin Rao , Teng Liu , Yang Liu , Ji Bian , Feng Zhu , Le Luo