作者机构:[1]Key Laboratory for Physical Electronics and Devices of the Ministry of Education & Shaanxi Key Lab of Information Photonic Technique, Xi ' an Jiaotong University,China Xi 'an 710049, [2]Department of Physics, University of Arkansas, Fayetteville,USA Arkansas 72701, [3]National Laboratory of Solid State Microstructures and Department of Physics, Nanjing University,China Nanjing 210093
相关基金:This work was supported by the Na- tional Basic Research Program of China (973 Program) (Grant No. 2012CB921804) and the National Natural Science Foundation of China (Grant Nos. 10974151, 61078002, 61078020, 11104214, 61108017, 11104216, and 61205112).