报告题目：Single-molecule Raman mapping with sub-nm resolution

报 告 人：Zhenchao Dong (董振超），Hefei National Laboratory for Physical Sciences at the Microscale and Synergetic Innovation Center of Quantum Information & Quantum Physics,University of Science and Technology of China

报告时间：2014年6月19日16：00

报告地点：理科楼郑裕彤大讲堂

报告摘要：Visualizing individual molecules with chemical recognition is a longstanding target in catalysis, bio-science, nanotechnology, and materials science. Molecular vibrations provide a valuable “fingerprint” for this identification. The spectroscopy based on tip-enhanced Raman scattering (TERS) has opened a path to obtain enhanced vibrational signals thanks to the strong localized plasmonic field originated at the tip apex. In this talk, I shall demonstrate single-molecule Raman spectroscopic mapping with unprecedented spatial resolution down to sub-nm, resolving even the inner structure of a single molecule and its configuration on the surface [1]. This is achieved by a delicate spectral-matching technique that invokes a double-resonance process and resultant nonlinear optical effect, thanks to the exquisite tuning capability provided by low-temperature ultrahigh-vacuum scanning tunneling microscopy. Our nonlinear TERS technique features the use of only a continuous wave laser rather than two pulse lasers. The central message delivered from our findings is: Raman spectromicroscopy has gone intra-molecular and sub-nanometer, which opens up a new avenue to probe surface chemical reactions, nonlinear optical processes, photochemistry, and bio-imaging at the single-molecule scale.

References

[1] R. Zhang, Y. Zhang, Z. C. Dong*, S. Jiang, C. Zhang, L. G. Chen, L. Zhang, Y. Liao, J. Aizpurua, Y. Luo, J. L. Yang , and J. G. Hou*, "Chemical mapping of a single molecule by plasmon enhanced Raman scattering", Nature 498 (2013) 82-86.