exposedtoambientenvironment方案.PDFVIP

Robustness of topological order and formation of quantum well states in topological insulators exposed to ambient environment a a a a a a a a Chaoyu Chen , Shaolong He , Hongming Weng , Wentao Zhang , Lin Zhao , Haiyun Liu , Xiaowen Jia , Daixiang Mou , a a a a a a a a Shanyu Liu , Junfeng He , Yingying Peng , Ya Feng , Zhuojin Xie , Guodong Liu , Xiaoli Dong , Jun Zhang , Xiaoyang Wangb b b b b b , Qinjun Peng , Zhimin Wang , Shenjin Zhang , Feng Yang , Chuangtian Chen , Zuyan Xub a a a,1 , Xi Dai , Zhong Fang , and X. J. Zhou a Beijing National Laboratory for Condensed Matter Physics, Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China; and bTechnical Institute of Physics and Chemistry, Chinese Academy of Sciences, Beijing 100190, China Edited by* E. Ward Plummer, Louisiana State University, Baton Rouge, LA, and approved January 18, 2012 (received for review September 24, 2011) The physical property investigation (like transport measurements) pological insulators depend sensitively on the composition, x , as and ultimate application of the topological insulators usually in- shown in Fig. 1. The single crystal samples here were all cleaved volve surfaces that are exposed to ambient environment (1 atm in situ and measured at 30 K in an ultrahigh vacuum (UHV) cham- and room temperature). One critical issue is how the topological ber with a base pressure better than 5 × 10−11 to