English
Related papers

Related papers: Leggett-Garg Inequalities

200 papers

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

Bell inequalities are a consequence of measurement incompatibility (not, as generally thought, of nonlocality). In classical terms, this is equivalent to contextuality -- measurement devices do have a significant effect. Contextual models…

Quantum Physics · Physics 2007-05-23 Peter Morgan

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

We revisit the study of the violation of the Leggett-Garg inequality in neutrino oscillation data as a mean to test some of the fundamental aspects of quantum mechanics. In particular, we consider the results of the Daya Bay and RENO…

High Energy Physics - Phenomenology · Physics 2025-03-26 Ricardo Zamora Barrios , Mario A. Acero

Weak measurement has provided new insight into the nature of quantum measurement, by demonstrating the ability to extract average state information without fully projecting the system. For single qubit measurements, this partial projection…

For multilevel spin systems, robustness of the quantum mechanical (QM) violation of macrorealism (MR) with respect to coarse grained measurements is investigated using three different necessary conditions of MR, namely, the Leggett-Garg…

Quantum Physics · Physics 2016-12-28 Shiladitya Mal , Debarshi Das , Dipankar Home

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

We present generic Bell inequalities for multipartite multi-dimensional systems. The inequalities that any local realistic theories must obey are violated by quantum mechanics for even-dimensional multipartite systems. A large set of…

Quantum Physics · Physics 2009-11-11 W. Son , Jinhyoung Lee , M. S. Kim

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

We demonstrate violation of objective realism in quantum world using unconstrained weak measurements. Instead of limited Leggett-Garg approach with artificial bounds on the observed values, we assume two identical and indepenent weak…

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 quantum nature of neutrino oscillations would be reflected in the mismatch between the neutrino survival probabilities with and without an intermediate observation. We propose this ``quantum mismatch'' as a measure of quantumness in…

High Energy Physics - Phenomenology · Physics 2023-04-06 Dibya S. Chattopadhyay , Amol Dighe

The Leggett and Garg Inequality (LGI) is a test of the classical behaviour of an observed system, in the case of a single measurement channel monitored at different times. Here we report LGI violation in cognitive tasks consisting in the…

Neurons and Cognition · Quantitative Biology 2013-05-27 F. T. Arecchi , A. Farini , N. Megna

Macrorealism formalizes the intuitive notion that at any given time the system occupies a definite state and that the evolution of the system is independent of the measurements performed on it, in contrast to the principles of quantum…

Characterization of quantum devices received from unknown providers is a significant primary task for any quantum information processing protocol. Self-testing protocols are designed for this purpose of certifying quantum components from…

Quantum Physics · Physics 2021-06-09 Ananda G. Maity , Shiladitya Mal , Chellasamy Jebarathinam , A. S. Majumdar

Macro-realistic description of systems is based majorly on two basic intuitions about the classical world, namely, macrorealism per se, that is, the system is always in a distinct state, and non-invasive measurements, that is, measurements…

Quantum Physics · Physics 2025-06-16 Shubhayan Sarkar

Measurement incompatibility and quantum non-locality are two key features of quantum theory. Violations of Bell inequalities require quantum entanglement and incompatibility of the measurements used by the two parties involved in the…

Mathematical Physics · Physics 2023-03-30 Faedi Loulidi , Ion Nechita

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

The basic Leggett inequalities, i.e. those inequalities in which the particular assumptions of Leggett's hidden-variable model (e.g. Malus law) were not yet introduced, are usually derived using hidden-variable distributions of…

Quantum Physics · Physics 2009-12-21 Sofia Wechsler

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