Twelve years before the quantum no-cloning theorem

TL;DR

This paper reveals that the fundamental quantum no-cloning theorem was implicitly proven in 1970, twelve years before its widely recognized publication in 1982, challenging the historical timeline of quantum information theory.

Contribution

It uncovers and analyzes an earlier explicit proof of the no-cloning theorem from 1970, predating the well-known 1982 publication.

Findings

Park's 1970 paper contains an explicit proof of no-cloning.

The 1970 proof predates the widely recognized theorem by twelve years.

Historical understanding of the theorem's origin is revised.

Abstract

The celebrated quantum no-cloning theorem establishes the impossibility of making a perfect copy of an unknown quantum state. The discovery of this important theorem for the field of quantum information is currently dated 1982. I show here that an article published in 1970 [J. L. Park, Foundations of Physics, 1, 23-33 (1970)] contained an explicit mathematical proof of the impossibility of cloning quantum states. I analyze Park's demonstration in the light of published explanations concerning the genesis of the better-known papers on no-cloning.