An introduction to quantum annealing

Dipartimento di Scienze dell'Informazione Università degli Studi di Milano, via Comelico 39/41, 20135 Milano, Italy; tamascelli@dsi.unimi.it

Received: 10 February 2010
Accepted: 18 November 2010

Abstract

Quantum annealing, or quantum stochastic optimization, is a classical randomized algorithm which provides good heuristics for the solution of hard optimization problems. The algorithm, suggested by the behaviour of quantum systems, is an example of proficuous cross contamination between classical and quantum computer science. In this survey paper we illustrate how hard combinatorial problems are tackled by quantum computation and present some examples of the heuristics provided by quantum annealing. We also present preliminary results about the application of quantum dissipation (as an alternative to imaginary time evolution) to the task of driving a quantum system toward its state of lowest energy.