作者机构:[1]Key Laboratory of Advanced Photonic and Electronic Materials, Department of Physics, Nanjing University, Nanjing 210093, China
相关基金:Project supported by State Key Development Program for Basic Research of China (No. 2006CB6049), the National Hi-Tech Research and Development Program of China (No. 2006AA03A142), and the National Natural Science Foundation of China (Nos. 60721063, 60731160628, 60820106003).