| AVS 64th International Symposium & Exhibition | |
| Scanning Probe Microscopy Focus Topic | Monday Sessions |
| Session SP+2D+AS+NS+SS-MoA |
| Session: | Probing Electronic and Transport Properties |
| Presenter: | Wonhee Ko, Oak Ridge National Laboratory |
| Authors: | W. Ko, Oak Ridge National Laboratory S.M. Hus, Oak Ridge National Laboratory Y.P. Chen, Purdue University A.-P. Li, Oak Ridge National Laboratory |
| Correspondent: | Click to Email |
Conversion between the charge and the spin signal is a core technology for detection of many spin-related phenomena and for the realization of spintronic devices. Topological insulators are promising candidate for such purpose because of their surface states with non-trivial spin texture. The surface states electrons have the spin and the momentum locked to each other, so the electrical current can induce the uneven shift in the spin-dependent chemical potential for different spin directions. In this talk, we utilized spin-polarized four-probe scanning tunneling microscopy to probe the spin-dependent chemical potential of the topological insulators. Utilizing ferromagnetic tips and variable probe-spacing measurements, we detected non-vanishing spin-dependent chemical potential induced by the charge current. Various tip and surface conditions were tested to confirm its origin from the spin of charge carriers through the surface states. The result demonstrates the generation of excessive spins only by electrical means in topological insulators, which would become the critical component for the future spintronic applications.
This research was performed at the Center for Nanophase Materials Sciences which is a DOE Office of Science User Facility.