No Fine Theorem for Macrorealism: Limitations of the Leggett-Garg Inequality.

@article{Clemente2016NoFT,
  title={No Fine Theorem for Macrorealism: Limitations of the Leggett-Garg Inequality.},
  author={Lucas Clemente and Johannes Kofler},
  journal={Physical review letters},
  year={2016},
  volume={116 15},
  pages={
          150401
        }
}
Tests of local realism and macrorealism have historically been discussed in very similar terms: Leggett-Garg inequalities follow Bell inequalities as necessary conditions for classical behavior. Here, we compare the probability polytopes spanned by all measurable probability distributions for both scenarios and show that their structure differs strongly between spatially and temporally separated measurements. We arrive at the conclusion that, in contrast to tests of local realism where Bell… 

Figures and Tables from this paper

Necessary and sufficient conditions for macrorealism using two and three-time Leggett-Garg inequalities
The Leggett-Garg (LG) inequalities were introduced, as a temporal parallel of the Bell inequalities, to test macroscopic realism -- the view that a macroscopic system evolving in time possesses
Necessary and sufficient conditions for macrorealism using two- and three-time Leggett-Garg inequalities
  • J.J.Halliwell
  • Philosophy
    Journal of Physics: Conference Series
  • 2019
The Leggett-Garg (LG) inequalities were introduced, as a temporal parallel of the Bell inequalities, to test macroscopic realism – the view that a macroscopic system evolving in time possesses
Leggett-Garg macrorealism and the quantum nondisturbance conditions
We investigate the relation between a refined version of Leggett and Garg conditions for macrorealism, namely the no-signaling-in-time (NSIT) conditions, and the quantum mechanical notion of
A Stronger Theorem Against Macro-realism
Macro-realism is the position that certain "macroscopic" observables must always possess definite values: e.g. the table is in some definite position, even if we don't know what that is precisely.
Leggett-Garg tests of macrorealism: Checks for noninvasiveness and generalizations to higher-order correlators
In the tests for macrorealism proposed by Leggett and Garg, the temporal correlation functions of a dichotomic variable Q must be measured in a non-invasive way to rule out alternative classical
Constraints on macroscopic realism without assuming non-invasive measurability
  • R. Hermens, O. Maroney
  • Philosophy
    Studies in History and Philosophy of Science Part B: Studies in History and Philosophy of Modern Physics
  • 2018
Interference experiment, anomalous weak value, and Leggett-Garg test of macrorealism
Macrorealism is a classical world view asserting that the properties of macro-objects exist independently and irrespective of observation. One practical approach to test this view in quantum theory
Light polarization measurements in tests of macrorealism
According to the world view of macrorealism, the properties of a given system exist prior to and independent of measurement, which is incompatible with quantum mechanics. Leggett and Garg put forward
Leggett-Garg tests for macrorealism: Interference experiments and the simple harmonic oscillator
Leggett-Garg (LG) tests for macrorealism were originally designed to explore quantum coherence on the macroscopic scale. Interference experiments and systems modelled by harmonic oscillators provide
Fine's theorem for Leggett-Garg tests with an arbitrary number of measurement times
If the time evolution of a system can be understood classically, then there must exist an underlying probability distribution for the variables describing the system at all times. It is well known
...
1
2
3
4
5
...

References

SHOWING 1-10 OF 95 REFERENCES
Condition for macroscopic realism beyond the Leggett-Garg inequalities
In 1985, Leggett and Garg put forward the concept of macroscopic realism (macrorealism) and, in analogy to Bell's theorem, derived a necessary condition in terms of inequalities, which are now known
Leggett-Garg inequalities and no-signaling in time: A quasiprobability approach
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
Addressing the Clumsiness Loophole in a Leggett-Garg Test of Macrorealism
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
Modeling Leggett-Garg-inequality violation
TLDR
An operational model is introduced where the effects of invasiveness are controllable through a parameter associated with what is called the measurability of the physical system, which leads to different generalized measurements that can be associated with the dimensionality of a system.
Necessary and Sufficient Conditions for an Extended Noncontextuality in a Broad Class of Quantum Mechanical Systems.
TLDR
This work derives necessary and sufficient conditions for the existence of a maximally noncontextual description in a broad class of systems including Klyachko-Can-Binicioğlu-Shumvosky-type (KCBS), EPR-Bell-type, and Leggett-Garg-type systems.
Necessary and sufficient conditions for macroscopic realism from quantum mechanics
Macroscopic realism, the classical world view that macroscopic objects exist independently of and are not influenced by measurements, is usually tested using Leggett-Garg inequalities. Recently,
Leggett-Garg inequalities and the geometry of the cut polytope
The Bell and Leggett-Garg tests offer operational ways to demonstrate that nonclassical behavior manifests itself in quantum systems, and experimentalists have implemented these protocols to show
Experimental violation of the Leggett-Garg inequality under decoherence
TLDR
These generalized LG inequalities test the evolution trajectory of the photon and are shown to be maximally violated in a coherent evolution process and can be used to set a boundary of the classical realistic description.
Leggett-Garg Inequalities
In contrast to the spatial Bell's inequalities, which probe entanglement between spatially-separated systems, the Leggett-Garg inequalities test the correlations of a single system measured at
Quantum correlations in the temporal Clauser-Horne-Shimony-Holt (CHSH) scenario
We consider a temporal version of the Clauser–Horne–Shimony–Holt (CHSH) scenario using projective measurements on a single quantum system. It is known that quantum correlations in this scenario are
...
1
2
3
4
5
...