Department of Physics, Sogang University, Seoul 121-742, Korea, Department of Physics, Konkuk University, Seoul 143-701, Korea, Korea Institute for Advanced Study, Seoul 130-722, Korea, Department of Physics, University of California at Berkeley, Berkeley, California 94720, Materials Sciences Division, Lawrence Berkeley National Laboratory, Berkeley, California 94720, Quantum Photonic Science Research Center, Hanyang University, Seoul 133-791, Korea(2008-10-29時点)
