On the Role of Entanglement in Schroedinger's Cat Paradox

TL;DR

This paper clarifies the role of entanglement in Schrödinger's cat paradox, arguing that superpositions of entangled states do not require decoherence to explain the absence of macroscopic superpositions, thus resolving the paradox.

Contribution

It distinguishes between superpositions of macroscopic states and entangled states, showing that the paradox can be addressed without decoherence, and proposes modified quantum optical experiments.

Findings

Superpositions of entangled states do not lead to paradoxical macroscopic superpositions.

Decoherence is not necessary to explain the absence of macroscopic superpositions in certain cases.

Modified quantum optical experiments support the resolution of the paradox.

Abstract

In this paper we re-investigate the core of Schroedinger's 'cat paradox'. We argue that one has to distinguish clearly between superpositions of macroscopic cat states and superpositions of entangled states which comprise both the state of the cat. It is shown, that in the first instance recurrence to decoherence or other mechanisms is not necessary in this special case in order to explain the absence of macroscopic superpositions. Additionally, we present modified versions of two quantum optical experiments as experimenta crucis. Applied rigorously, quantum mechanical formalism reduces the problem to a mere pseudo-paradox.