| AVS 66th International Symposium & Exhibition | |
| Materials and Processes for Quantum Information, Computing and Science Focus Topic | Wednesday Sessions |
| Session QS+2D+EM+MN+NS+VT-WeM |
| Session: | Material Systems and Applications for Quantum Sciences |
| Presenter: | Robert Walko, The Ohio State University |
| Authors: | R. Walko, The Ohio State University S.M. Mueller, The Ohio State University S. Gant, The Ohio State University J.J. Repicky, The Ohio State University S.J. Tjung, The Ohio State University E. Lang, The Ohio State University E. Fuller, The Ohio State University K. Werner, The Ohio State University F. Bergmann, Bergmann Messgeraete Entwicklung E. Chowdhury, The Ohio State University J.A. Gupta, The Ohio State University |
| Correspondent: | Click to Email |
In this work we present a scanning tunneling microscopy (STM) study of tip-induced switching of charge states in individual indium adatoms on the InSb(110) surface. These adatoms are deposited onto the surface by controlled voltage pulses between the STM tip and the surface. We observe them in two distinct charge states: positive and neutral. Adatom-induced band bending from the positively charged state has been observed to induce a tenfold increase in surface conductance relative to the charge neutral state, the effect of which can be observed >100nm away from the indium adatom. When the STM tip is brought sufficiently close to the defect, electrons can tunnel from the tip to the defect and cause the charge state to switch from positive to neutral. During imaging, this switching leads to a “crater” feature around the defect due to the lower conductance of the charge neutral state. The spatial extent of the crater can be tuned via the applied bias voltage, the tunneling set-point current, and photoillumination of the surface. We explain this phenomenon using a model of competing rates between the filling and emptying of the defect state, similar to dangling bonds on the Si(111) surface.
This work acknowledges funding from the DOE (# DE-SC0016379)