Bill Fefferman was a postdoctoral researcher in QuICS. His research interests included quantum computation and information, with a specific focus on complexity theory. Fefferman analyzed the power of quantum computers from a complexity theoretic point of view. Despite the prevailing belief that quantum computers are more powerful than their classical counterparts this remains a conjecture backed by little formal evidence. Fefferman's research attempts to establish a rigorous basis for this belief. After QuICS, he continued on to NIST, but is spending the first year of it as a postdoc at Berkeley.