Public talk: How Does a Quantum Computer Work?

This is an open lecture for the general public and all interested parties!

Quantum mechanics, now about a century old, is a very successful physical theory of
matter on a small scale. From its first description until today, it has surprised scientists and
laypersons alike by the strange behaviour it attributes to particles, atoms, and molecules.
This behaviour can be characterized by the keywords Uncertainty, Superposition, and
Entanglement.
It took about sixty years before it was realized that these three characteristics do not just
express a certain vagueness and strangeness of matter on a small scale but can actually
be USEd to our advantage. In 1994 Peter Shor made this idea concrete by devising an
algorithm that would enable large arrays of quantum systems to perform specific
calculations (factoring large integers), which are impossible to do in practice on any
classical device. With this algorithm, present-day cryptographic schemes can be broken,
provided such "quantum computers” can be made to work.
Starting from a discussion of the "two-slit experiment”, we sketch the working of Shor's
algorithm and discuss the possibilities of future quantum computers.

About the speaker: Hans Maassen is a dutch mathematical physicist and emeritus professor specializing in quantum probability and quantum information theory. Standing out among his discoveries is the entropic uncertainty relation, named after himself and Jos Uffink, a fundamental
inequality in quantum mechanics.