Massachusetts Institute of Technology

Title: Quantum computation with NMR: Factoring 15 and beyond.

Abstract: When bits of information are represented by objects as small as atoms, their behavior ceases to obey the classical laws of physics normally assumed in computation, as quantum mechanics takes over. This new realm of quantum information offers computational capabilities exponentially greater than classical computers, for certain problems. We report on an experimental implementation of the simplest instance of Shor's quantum factoring algorithm, using seven spin-1/2 nuclei in a molecule, manipulated with room temperature liquid-state nuclear magnetic resonance, to obtain the factors of the number 15. This work demonstrates experimental and theoretical techniques for precise control and modeling of complex quantum computers, including a cooling method based on information compression, and a parameter-free, predictive model of decoherence effects, which may scale to future AMO implementations.