Scientific Reports 6: Article number: 22027; 10.1038/srep22027 published online: February232016; updated: June102016
In the original version of this Article, an additional affiliation for Lin Chen and YiMing Zhu was omitted. The correct affiliation is listed below:
Cooperative Innovation Center of Terahertz Science, Chengdu 611731, China.
This error has now been corrected in the PDF and HTML versions of the Article.