Physics and Astronomy Colloquium

There is a deep connection between Physics and Computation.
Indeed, any computation can be represented as a physical process. In a keynote speech at MIT in 1981 Richard Feynman raised some provocative questions in connection to the simulation of physical phenomena using a special machine called a "Quantum Computer." Such a device was intended to mimic physical processes exactly the same as Nature. At the time it was known that deterministic simulations of quantum phenomena in classical computers required a number of resources that scaled exponentially with the number of degrees of freedom. Certainly, remarks coming from such an influential figure generated widespread interest in these ideas, and today after 27 years there are still open questions. What kind of physical phenomena can be mimicked with a Quantum Computer?, How?, and What are its limitations? Attempting to answer these questions is what this talk is about. I will illustrate the main ideas by mimicking simple physical phenomena borrowed from condensed matter physics, and present experimental results performed in a liquid Nuclear Magnetic Resonance Quantum Computer.