On November 15, Professor Frank Hegmann, who is granted by the Chinese Academy of Sciences President¡¯s International Fellowship for Visiting Scientists, gave a talk in the institute of solid state physics. The title of the talk is ¡°Imaging ultrafast dynamics on the nanoscale with terahertz scanning tunneling microscopy¡±. Professor Zhi Zeng hosted this talk.
In this talk, Professor Hegmann presented the applications of Terahertz spectroscopy on nanoscale materials. Terahertz (THz) pulses are ideal for probing ultrafast carrier dynamics and the nature of conduction in materials. The ability to directly probe ultrafast phenomena on the nanoscale is essential to people¡¯s understanding of excitation dynamics on surfaces and in nanomaterials. However, the spatial resolution is limited due to the long wavelength of THz wave. Professor Hegmann developed a new ultrafast STM techniquethat coupled terahertz (THz) pulses to the scanning probe tip of an STM, which can provide simultaneous 0.5 ps time resolution and 2 nm spatial resolutionunder ambient laboratory conditions. He discussed how THz-STM works and its potential for probing sub-picosecond dynamics on surfaces with atomic resolution.This talk attracted a lot of attentions and isvery impressive for the audience.
Prof. Frank Hegmann in the presentation (imaged by WANG Yuan)
Biography of Frank Hegmann:
Frank Hegmann received his PhD in Physics from McMaster University in 1994 and then worked as a postdoctoral researcher at the Center for Terahertz Science and Technology at the University of California, Santa Barbara. In 1997, he started as an assistant professor in the Department of Physics at the University of Alberta studying ultrafast dynamics in materials using time-resolved terahertz (THz) pulse spectroscopy. He is currently a Professor in Physics and AITF Strategic Chair in Terahertz Science and Technology with research interests in THz pulse spectroscopy, ultrafast imaging, THz-STM, terahertz nonlinear dynamics, and biological effects of intense THz pulses.