Introduction to Quantum Computing

By Ludovic Noirie, 2019/09/23.
Quantum tekleportation algorithm

Abstract

When I was student, I was interested in quantum optics: my first paper was about quantum non-linear optics (Squeezing due to cascaded second-order nonlinearities in quasi-phase-matched media by L. Noirie, P. Vidakovic, and J. A. Levenson). Quantum computing has become a new hype in telecommunication and computing. So I wanted to understand by myself how quantum computing works (thanks Wikipedia!).

Starting with a reminder of quantum mechanics principles, my presentation explains what is a “quantum computer”, what are “qubits”, “quantum registers”, “quantum logical gates” and give some examples of “quantum algorithms” such as quantum “teleportation”, Shor’s algorithm for integer factorization and several other ones. It also shows how one can play with quantum computers (python libraries, LaTeX packages, web sites).

In terms of knowledge requirement, you just need to know a bit of linear algebra (calculation with square matrices on complex numbers) and accept the quantum physical rules as they are (maybe the most difficult aspect!): a quantum computer is just a system that processes unitary transformations on complex vectors (i.e., multiplications by unitary complex matrices)!

Context

This presentation will be given at LINCS in two parts:

Materials of this presentation (update 2019/09/23)