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Related papers: A macrorealistic test in hybrid quantum optomechan…

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We propose here a scheme, based on the measurement of quadrature phase coherence, aimed at testing the Clauser-Horne-Shimony-Holt Bell inequality in an optomechanical setting. Our setup is constituted by two optical cavities dispersively…

Quantum Physics · Physics 2018-10-18 Juuso Manninen , Muhammad Asjad , Risto Ojajärvi , Petri Kuusela , Francesco Massel

Probing quantum entanglement with macroscopic objects allows us to test quantum mechanics in new regimes. One way to realize such behavior is to couple a macroscopic mechanical oscillator to a continuous light field via radiation pressure.…

Quantum Physics · Physics 2024-03-07 Su Direkci , Klemens Winkler , Corentin Gut , Klemens Hammerer , Markus Aspelmeyer , Yanbei Chen

We show how a test of macroscopic realism based on Leggett-Garg inequalities (LGIs) can be performed in a macroscopic system. Using a continuous-variable approach, we consider quantum non-demolition (QND) measurements applied to atomic…

The Leggett-Garg inequality (LGI), based on the notions of realism and noninvasive measurability, is applied in the context of a linear harmonic oscillator. It is found that merely through observing at various instants which region of the…

Quantum Physics · Physics 2015-09-02 S. Bose , D. Home , S. Mal

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

We discuss the use of inequalities of the Leggett-Garg type (LGtI) to witness quantum coherence and present the first experimental violation of this type of inequalities using a light-matter interfaced system. By separately benchmarking the…

Quantum Physics · Physics 2015-09-11 Zong-Quan Zhou , Susana F. Huelga , Chuan-Feng Li , Guang-Can Guo

We consider a generic optomechanical system, consisting of a driven optical cavity and a movable mirror attached to a cantilever. Systems of this kind (and analogues) have been realized in many recent experiments. It is well known that…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Max Ludwig , Björn Kubala , Florian Marquardt

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…

"Macrorealism" posits that a system possesses definite properties at all times and that we can discover these properties, in principle, without disturbing the system's subsequent behaviour. The Leggett-Garg inequalities are derived under…

Quantum Physics · Physics 2026-05-22 Arush Garg , Jonathan Halliwell , Taejas Venkataraman

The Leggett-Garg inequality (LGI) distinguishes nonmacrorealistic channels from macrorealistic ones by constraining the experimental outcomes of the underlying system. In this work, we propose a class of channels which, initially, cannot…

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

Macroscopic realism is a set of assumptions about how we experience the world at a classical level. While the Leggett-Garg inequalities are temporal correlations that are violated by quantum systems not obeying such macrorealism, the…

Quantum Physics · Physics 2025-12-23 Manish Ramchander , Arul Lakshminarayan

We analyze the continuous measurement of two non-commuting observables for a qubit, and investigate whether the simultaneously observed noisy signals are consistent with the evolution of an equivalent classical system. Following the…

Quantum Physics · Physics 2016-12-28 Luis Pedro García-Pintos , Justin Dressel

Quantum mechanics has predicted many counterintuitive phenomena in daily life, and has changed our view of the world. Among such predictions, the existence of a macroscopic object in superposition is especially unbelievable. As Einstein…

Mesoscale and Nanoscale Physics · Physics 2009-05-15 Toshiyuki Fujii , Munehiro Nishida , Noriyuki Hatakenaka

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

Cavity optomechanics, a promising platform to investigate macroscopic quantum effects, has been widely used to study nonreciprocal entanglement with Sagnec effect. Here we propose an alternative way to realize nonreciprocal entanglemment…

Quantum Physics · Physics 2023-08-08 Jiaojiao Chen , Xiao-Gang Fan , Wei Xiong , Dong Wang , Liu Ye

In 1985, Leggett and Garg (1985 Phys. Rev. Lett. 54 857) proposed a Bell-like inequality to test (in)compatibility between two fundamental concepts of quantum mechanics. The first concept is 'macroscopic realism', which is the quality of a…

Quantum Physics · Physics 2011-05-13 A M Souza , I S Oliveira , R S Sarthour

We formulate a spatial extension of the Leggett-Garg inequality by considering three distant observers locally measuring a many-body system at three subsequent times. The spatial form, in particular, is specially suited to analyze…

Quantum Physics · Physics 2025-07-08 Guillem Müller-Rigat , Donato Farina , Maciej Lewenstein , Andrea Tononi

We investigate the nonclassicality of an open quantum system using Leggett-Garg inequality (LGI) which test the correlations of a single system measured at different times. Violation of LGI implies nonclassical behavior of the open system.…

Quantum Physics · Physics 2017-04-11 Md. Manirul Ali , Po-Wen Chen

Quantum Hypothesis Testing has shown the advantages that quantum resources can offer in the discrimination of competing hypothesis. Here, we apply this framework to optomechanical systems and fundamental physics questions. In particular, we…

Quantum Physics · Physics 2021-04-13 Marta Maria Marchese , Alessio Belenchia , Stefano Pirandola , Mauro Paternostro