Epistemic vs Ontic Classification of quantum entangled states?

TL;DR

This paper argues that the classification of quantum states into entangled and factorizable is fundamentally epistemic and dependent on the choice of degrees of freedom, asserting all states are essentially entangled.

Contribution

It challenges the traditional dichotomy by proposing that all quantum states are inherently entangled, with factorizability being a matter of perspective based on degrees of freedom.

Findings

Factorizable states are entangled under different degrees of freedom.

No ontologically superior partition of quantum systems exists.

All quantum states are objectively entangled.

Abstract

In this brief paper, starting from recent works, we analyze from conceptual point of view this basic question: can the nature of quantum entangled states be interpreted ontologically or epistemologically? According to some works, the degrees of freedom (and the tool of quantum partitions) of quantum systems permit us to establish a possible classification between factorizable and entangled states. We suggest, that the "choice" of degree of freedom (or quantum partitions), even if mathematically justified introduces an epistemic element, not only in the systems but also in their classification. We retain, instead, that there are not two classes of quantum states, entangled and factorizable, but only a single class of states: the entangled states. In fact, the factorizable states become entangled for a different choice of their degrees of freedom (i.e. they are entangled with respect to other observables). In the same way, there are no partitions of quantum systems which have an ontologically superior status with respect to any other. For all these reasons, both mathematical tools utilize(i.e quantum partitions or degrees of freedom) are responsible for creating an improper classification of quantum systems. Finally, we argue that we cannot speak about a classification of quantum systems: all quantum states exhibit a uniquely objective nature, they are all entangled states.