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arXiv · 1807.08457

Optical Stark Effect of a Single Defect on TiO2(110) Surface

Lihuan Sun·Anning Dong·Jianmei Li·Dong Hao·Xiangqian Tang·Shichao Yan·Yang Guo·Xinyan Shan·Xinghua Lu
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Abstract

Probing optical Stark effect at the single-molecule or atomic scale is crucial for understanding many photo-induced chemical and physical processes on surfaces. Here we report a study about optical Stark effect of single atomic defects on TiO2(110) surface with photo-assisted scanning tunneling spectroscopy. When a laser is coupled into the tunneling junction, the mid-gap state of OH-O2 defects changes remarkably in the differential conductance spectra. As laser power gradually increases, the energy of the mid-gap state shifts away from the Fermi level with increase in intensity and broadening of peak width. The observation can be explained as optical Stark effect with the Autler-Townes formula. This large optical Stark effect is due to the tip-enhancement and the strong dipole moment in the transient charged state during electron tunneling. Our study provides new aspects in exploring electron-photon interactions at the microscopic scale.

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Lihuan Sun, Anning Dong, Jianmei Li, Dong Hao, Xiangqian Tang, Shichao Yan, Yang Guo, Xinyan Shan, Xinghua Lu. 2018-07-24. Optical Stark Effect of a Single Defect on TiO2(110) Surface. https://doi.org/10.1103/physrevb.98.081402

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