Evidence of entanglement, or: Is Schr\"{o}dinger's cat really entangled?

TL;DR

This paper clarifies the concept of quantum entanglement, addressing common misconceptions through mathematical explanations and examples, using Schrödinger's cat paradox to illustrate the issues.

Contribution

It provides a clearer understanding of entanglement by analyzing misconceptions and offering mathematical clarification with practical examples.

Findings

Clarifies the notion of entanglement in quantum physics.

Highlights common misconceptions and their resolutions.

Uses Schrödinger's cat paradox to illustrate key points.

Abstract

Quantum effects and, in particular, entanglement are by now widely recognized in all areas of physics and related fields. However, we feel that the precise notion of entanglement---though mathematically well-defined---still generates confusion even in the academic environment. Our aim in this article is to point out and clarify some aspects of the notion of entanglement, in particular with respect to observable quantities. We do this by illustrating common misconceptions with Schr\"{o}dinger's cat paradox, explain them in mathematical terms and provide examples where misunderstandings arise and how they can be solved.