AVS 60th International Symposium and Exhibition
    Surface Science Tuesday Sessions
       Session SS-TuP

Paper SS-TuP21
Atomic Force Microscopy Studies of Charge Transport Properties of Strained and Indented Topological Insulator

Tuesday, October 29, 2013, 6:00 pm, Room Hall B

Session: Surface Science Poster Session
Presenter: J.H. Hwang, KAIST, Republic of Korea
Authors: J.H. Hwang, KAIST, Republic of Korea
S. Kwon, KAIST, Republic of Korea
J. Park, Pohang University of Science and Technology, Republic of Korea
J. Lee, KAIST, Republic of Korea
J.S. Kim, Pohang University of Science and Technology, Republic of Korea
H.-K. Lyeo, Korea Research Institute of Standards and Science, Republic of Korea
J.Y. Park, KAIST, Republic of Korea
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We investigated the correlation between electrical transport and mechanical stress in Bi2Te2Se by using a conductive probe atomic force microscopy in an ultra-high vacuum environment. Uniform distribution of measured friction and current were observed over a single quintuple layer terrace, which is an indication of the uniform chemical composition of the surface. By measuring the charge transport of Bi2Te2Se surface as a function of the load applied by a tip to the sample, we found that the current density varies with applied load. The variation of current density was explained in light of the combined effect of the changes in the in-plane conductance and spin-orbit coupling that were theoretically predicted. We suppose that the local density of states is modified by tip-induced strain, but topological phase still remains. We exposed a clean topological insulator surface by tip-induced indentation. The surface conductance on the indented Bi2Te2Se surface was studied, and the role of surface oxide on the surface conductance is discussed.