Professor Clark has co-authored 140 research publications. He has established two of the country's most advanced research laboratories, the National Pulsed Magnet Laboratory and Semiconductor Nanofabrication Facility both central to the new Australian Research Council SRC for Quantum Computer Technology of which he is Director. Research highlights include the first (indirect) measurement of fractional electronic charge in the fractional quantum Hall regime and the elucidation of the critical role played by electron spin (cited by RB Laughlin in his Nobel Prize review). Important experiments also include the optical detection of the fractional quantum Hall effect and electron solid (Wigner crystal).