The field of quantum information encompasses the study of the representation, storing, processing, and accessing of information by quantum mechanical systems. The field grew from the investigations of the physical limits to computation initiated by Charles Bennett and Rolf Landauer. One of the first questions studied was whether quantum mechanics imposes any limits on what a computer can do, and it was shown by Richard Feynman that it does not. Earlier work by Paul Benioff had explored the possibilities of quantum Turing machines. Shortly after Feynman’s work, David Deutsch realized that not only is quantum mechanics not a problem for computation, it can also be an advantage. The major breakthrough in the field was Peter Shor’s factoring algorithm, which showed that a quantum computer can find the prime factors of integers in a time that scales as a polynomial of the size of the integer.