Schroedinger cats and quantum complementarity

TL;DR

This paper explains the Schrödinger cat paradox through quantum complementarity, showing the cat can have a definite value of a property complementary to being dead or alive, resolving the paradox within standard quantum theory.

Contribution

It demonstrates that the Schrödinger cat can have a well-defined complementary property, providing a new interpretation of the paradox using textbook quantum concepts.

Findings

The cat has a definite value of a property complementary to 'being dead or alive'

The paradox is explained via quantum complementarity within the Copenhagen interpretation

An Arduino simulation of Schrödinger's experiment is proposed for science outreach

Abstract

Complementarity tells us we cannot know precisely the values of all the properties of a quantum object at the same time: the precise determination of one property implies that the value of some other (complementary) property is undefined. E.g.the precise knowledge of the position of a particle implies that its momentum is undefined. Here we show that a Schroedinger cat has a well defined value of a property that is complementary to its ``being dead or alive'' property. Then, thanks to complementarity, it has an undefined value of the property ``being dead or alive''. In other words, the cat paradox is explained through quantum complementarity: of its many complementary properties, any quantum system, such as a cat, can have a well defined value only of one at a time. Schroedinger's cat has a definite value of a property which is complementary to ``being dead or alive'', so it is neither dead nor alive. Figuratively one can say it is both dead and alive. While this interpretation only uses textbook concepts (the Copenhagen interpretation), apparently it has never explicitly appeared in the literature. We detail how to build an Arduino based simulation of Schroedinger's experiment based on these concepts for science outreach events.