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Related papers: Inequivalent Leggett-Garg inequalities

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Quantum coherence is one of the primary non-classical features of quantum systems. While protocols such as the Leggett-Garg inequality (LGI) and quantum tomography can be used to test for the existence of quantum coherence and dynamics in a…

Quantum Physics · Physics 2012-12-04 Che-Ming Li , Neill Lambert , Yueh-Nan Chen , Guang-Yin Chen , Franco Nori

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…

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

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 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

Quantum mechanics violates Leggett-Garg inequalities because the operator formalism predicts correlations between different spin components that would correspond to negative joint probabilities for the outcomes of joint measurements.…

Quantum Physics · Physics 2015-03-20 Yutaro Suzuki , Masataka Iinuma , Holger F. Hofmann

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

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

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

The possibility of observing violations of temporal Bell inequalities, originally proposed by Leggett as a mean of testing the quantum mechanical delocalization of suitably chosen macroscopic bodies, is discussed by taking into account the…

Quantum Physics · Physics 2009-10-31 Tommaso Calarco , Marcello Cini , Roberto Onofrio

Macrorealism is a characteristic feature of many, but not all, classical systems. It is known, for example, that classical light can violate a Leggett-Garg inequality and, hence, reject a macrorealist interpretation. A recent experiment has…

Quantum Physics · Physics 2022-12-20 Brian R. La Cour

Recent experiments of Groeblacher et al. proved the violation of a Leggett-type inequality that was claimed to be valid for a broad class of non-local hidden-variable theories. The impossibility of constructing a non-local and realistic…

Quantum Physics · Physics 2008-11-10 F. De Zela

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

We investigate the violation of Leggett's inequality for non-local realism using entangled coherent states and various types of local measurements. We prove mathematically the relation between the violation of the Clauser-Horne-Shimony-Holt…

Quantum Physics · Physics 2015-03-17 Chang-Woo Lee , Mauro Paternostro , Hyunseok Jeong

Contextuality means non-existence of a joint distribution for random variables recorded under mutually incompatible conditions, subject to certain constraints imposed on how the identity of these variables may change across these…

Quantum Physics · Physics 2015-02-06 Ehtibar N. Dzhafarov , Janne V. Kujala

Macroscopic realism, as introduced by Leggett and Garg, is the world view in which properties of macroscopic systems exist independent of and are not influenced by measurement. Motivated by classical physical laws such as Newtonian…

Quantum Physics · Physics 2010-02-24 Johannes Kofler , Nikola Buric , Caslav Brukner

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

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 investigate violations of Leggett-Garg inequalities (LGIs) for a harmonic oscillator and a (1+1)-dimensional chiral scalar field with coherent-state projectors, which is equivalent to a heterodyne-type measurement scheme. For the…

Quantum Physics · Physics 2024-01-30 Tomoya Hirotani , Akira Matsumura , Yasusada Nambu , Kazuhiro Yamamoto

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