Correction to: Scientific Reports https://doi.org/10.1038/s41598-017-18229-6, published online 21 December 2017

In the original version of this Article, Guang-Can Guo, and not Chuan-Feng Li, was incorrectly listed as a corresponding author. The correct corresponding authors for this Article are Tao Tu and Chuang Feng Li. Correspondence and requests for materials should be addressed to Tao Tu (tutao@ustc.edu.cn) or Chuan-Feng Li (cfli@ustc.edu.cn). This error has now been corrected in the HTML and PDF versions of the Article.