A Relationship Between Nonphysical Quasi-probabilities and Nonlocality Objectivity
Abstract
Density matrices are the most general descriptions of quantum states, covering both pure and mixed states. Positive semidefiniteness is a physical requirement of density matrices, imposing nonnegative probabilities of measuring physical values. Separately, nonlocality is a property shared by some bipartite quantum systems, indicating a correlation of the component parts that cannot be described by local classical variables. In this work, we show that breaking the positive-semidefinite requirement and allowing states with a negative minimal eigenvalue arbitrarily close to zero, allows for the construction of states that are nonlocal under one component labelling but local when the labelling is interchanged. This is an observer-dependent nonlocality, showing the connection between nonlocal objectivism and negative quasi-probabilities.
Cite
@article{arxiv.2407.19061,
title = {A Relationship Between Nonphysical Quasi-probabilities and Nonlocality Objectivity},
author = {Colm Kelleher},
journal= {arXiv preprint arXiv:2407.19061},
year = {2024}
}
Comments
An error in the calculation of the eigenvalues for \beta^{T}\beta for the right-identity case (Sec. 3, eq. 8 line 1). In fact the eigenvalues are the same for both left- and right- identities, leaving the main result null and void