Weak measurements, non-classicality and negative probability
- URL: http://arxiv.org/abs/2006.12436v3
- Date: Mon, 25 Oct 2021 17:16:17 GMT
- Title: Weak measurements, non-classicality and negative probability
- Authors: Sooryansh Asthana and V. Ravishankar
- Abstract summary: It has been shown that nonexistence of a classical joint probability scheme gives rise to sufficiency conditions for nonlocality.
The crux of the paper is that the pseudo-probabilities, which can take negative values, can be directly measured as anomalous weak values.
- Score: 0.0
- License: http://creativecommons.org/licenses/by-nc-sa/4.0/
- Abstract: This paper establishes a direct, robust and intimate connection between (i)
non classicality tests for various quantum features, e.g., non-Boolean logic,
quantum coherence, nonlocality, quantum entanglement, quantum discord; (ii)
negative probability, and (iii) anomalous weak values. It has been shown
[Adhikary et al. Eur. Phys. J. D, 74(68):68, 2020] that nonexistence of a
classical joint probability scheme gives rise to sufficiency conditions for
nonlocality, a nonclassical feature not restricted to quantum mechanics. The
conditions for nonclassical features of quantum mechanics are obtained by
employing pseudo probabilities, which are expectation values of the parent
pseudo projections. The crux of the paper is that the pseudo-probabilities,
which can take negative values, can be directly measured as anomalous weak
values. We expect that this opens up new avenues for testing nonclassicality
via weak measurements, and also gives deeper insight into negative pseudo
probabilities which become measurable. A quantum game, based on violation of
classical probability rule is also proposed that can be played by employing
weak measurements.
Related papers
- Sufficient conditions, lower bounds and trade-off relations for quantumness in Kirkwood-Dirac quasiprobability [0.0]
Kirkwood-Dirac (KD) quasiprobability is a quantum analog of classical phase space probability.
It offers an informationally complete representation of quantum state.
How does such form of quantumness comply with the uncertainty principle which also arise from quantum noncommutativity?
arXiv Detail & Related papers (2024-05-14T05:44:07Z) - Testing trajectory-based determinism via time probability distributions [44.99833362998488]
Bohmian mechanics (BM) has inherited more predictive power than quantum mechanics (QM)
We introduce a prescription for constructing a flight-time probability distribution within generic trajectory-equipped theories.
We derive probability distributions that are unreachable by QM.
arXiv Detail & Related papers (2024-04-15T11:36:38Z) - Quantum speed limit for Kirkwood-Dirac quasiprobabilities [0.0]
We derive quantum speed limits for two-time correlation functions arising from statistics of measurements.
Our quantum speed limits are derived from the Heisenberg-Robertson uncertainty relation, and set the minimal time at which a quasiprobability can become non-positive.
As an illustrative example, we apply these results to a conditional quantum gate, by determining the optimal condition giving rise to non-classicality at maximum speed.
arXiv Detail & Related papers (2024-02-12T11:28:56Z) - Quantum coherence from Kirkwood-Dirac nonclassicality, some bounds, and operational interpretation [0.0]
We develop a faithful quantifier of quantum coherence based on the KD nonclassicality.
The KD-nonclassicality coherence captures simultaneously the nonreality and the negativity of the KD quasiprobability.
arXiv Detail & Related papers (2023-09-17T05:29:49Z) - Measurement incompatibility is strictly stronger than disturbance [44.99833362998488]
Heisenberg argued that measurements irreversibly alter the state of the system on which they are acting, causing an irreducible disturbance on subsequent measurements.
This article shows that measurement incompatibility is indeed a sufficient condition for irreversibility of measurement disturbance.
However, we exhibit a toy theory, termed the minimal classical theory (MCT), that is a counterexample for the converse implication.
arXiv Detail & Related papers (2023-05-26T13:47:00Z) - Quantum Discord Witness with Uncharacterized Devices [18.751513188036334]
We propose a new approach using uncharacterized measurements to witness quantum discord of an unknown bipartite state within arbitrary dimension system.
The feature of high robustness against device imperfections, such as loss-tolerance and error-tolerance, shows our method is experimentally feasible.
arXiv Detail & Related papers (2023-03-20T14:51:53Z) - Quantum Instability [30.674987397533997]
We show how a time-independent, finite-dimensional quantum system can give rise to a linear instability corresponding to that in the classical system.
An unstable quantum system has a richer spectrum and a much longer recurrence time than a stable quantum system.
arXiv Detail & Related papers (2022-08-05T19:53:46Z) - Experimental Test of Contextuality based on State Discrimination with a
Single Qubit [16.530085733940528]
We extend the scope of experimental test of contextuality to a minimal quantum system of only two states (qubit)
We observe a substantial violation of a no-go inequality derived by assuming non-contextuality.
We also quantify the contextual advantage of state discrimination and the tolerance against quantum noises.
arXiv Detail & Related papers (2022-06-22T04:03:04Z) - Quantum uncertainty as classical uncertainty of real-deterministic
variables constructed from complex weak values and a global random variable [0.0]
We construct a class of real-deterministic c-valued variables out of the weak values obtained via a non-perturbing weak measurement of quantum operators.
We show that this class of c-valued physical quantities'' provides a real-deterministic contextual hidden variable model for the quantum expectation value of a certain class of operators.
arXiv Detail & Related papers (2021-06-21T22:43:26Z) - Impossibility of creating a superposition of unknown quantum states [16.467540842571328]
We show that the existence of a protocol that superposes two unknown pure states with nonzero probability leads to violation of other no-go theorems.
Such a protocol can be used to perform certain state discrimination and cloning tasks that are forbidden in quantum theory.
arXiv Detail & Related papers (2020-11-04T13:25:42Z) - Mean Value of the Quantum Potential and Uncertainty Relations [0.0]
In this work we determine a lower bound to the mean value of the quantum potential for an arbitrary state.
We derive a generalized uncertainty relation that is stronger than the Robertson-Schr"odinger inequality and hence also stronger than the Heisenberg uncertainty principle.
arXiv Detail & Related papers (2020-02-04T19:25:01Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.