Seminar: The Untold History of the Quantum No-Cloning Theorem

The no-cloning theorem in quantum information is a celebrated result in the field which lies at the conceptual heart of subjects like quantum key distribution (QKD), quantum repeaters, quantum money and even quantum error correction. This important theorem establishes the impossibility of making a perfect copy of an unknown quantum state. A modern proof of the theorem requires just two lines. The discovery of its proof in quantum information is currently dated 1982 [Wootters, W., Zurek, W. Nature 299, 802–803 (1982) & Dieks, D. Physics Letters A 92.6, 271-272, (1982)].

But how is the no-cloning theorem different from the statement of Heisenberg’s uncertainty principle which had already been there since the late 1920s? And why did it take more than 50 years after the advent of quantum mechanics for the theorem to be “truly” discovered?

In this talk we will discuss the history behind the origins of this ubiquitous theorem and explore how the theorem had already been found by independent physicists at least four times before its crowning moment came in 1982. The story presents an essential character of the flow of science, which happens through neglected papers, rejected ideas, wrong proposals, and involves forgotten physicists, the “hippies” who saved physics, the scientific foresight of an ingenious reviewer and much more!