【21st.Dec.】 Ultrafast and microscopic view on the electronic relaxation dynamics in metal nanostructures
日期：2017-12-21
阅读：548
Topic: Ultrafast and microscopic view on the electronic relaxation dynamics in metal nanostructures
Speaker: Dr. Chongyue Yi, Department of Chemistry, Rice University , USA
Time:Thursday, December 21, 2017, 14:00 P M
Location: Room 528, Chemistry Building A (化学A楼528演讲厅)
Inviter: Prof. Dongping Zhong （仲冬平 教授）
摘要：
In metal nanoparticle, collective conduction electrons oscillation stimulated by incident light is known as surface plasmon resonance. When the material sampled is of sufficiently small size, electronic properties is dominated by quantum confinement.
By utilizing femtosecond time-resolved transient absorption spectroscopy, we presented structure-specific descriptions of the electronic energy relaxation dynamics of atomically precise monolayer-protected gold clusters (MPCs), which were selected for study because they bridged the expected transition from nonmetallic to metallic electron behavior. The quantifiable electron–phonon coupling process confirmed Au144 (1.8 nm) as the smallest MPC to exhibit metallic behavior and support surface plasmon resonance.
Additionally, by combing ultrafast and microscopic technique, the femtosecond transient absorption microscopy provided unique view of electron dynamics at single-particle level. We characterized the optomechanical coupling within plasmonic molecules on time-, space-, and energy-domain.
The coupling strength-dependent vibrational frequency shifts can be directly manipulated by precise tuning of the structure of the plasmonic molecule. The fundamental insight into optomechanical selection rules for the launching of vibrational modes was also provided.
These findings provide paves the way for new strategies to design devices based on GHz nano-mechanical resonator, such as ultrasensitive sensors, nano-electromechanical systems, and ultrafast optical switch.
个人简历
易崇岳博士，美国莱斯大学化学系博士后研究员。2009年毕业于华中科技大学。2015年获美国佛罗里达州立大学物理化学博士学位。之后美国莱斯大学纳米光子学实验室从事超快时间分辨显微光谱技术的研究与发展。
专业方向为超快激光光谱学，单分子光谱学，非线性光学，超强磁场光谱学以及纳米光子学。其工作在Proc. Natl. Acad. Sci. U.S.A., J. Am. Chem. Soc., Nano Lett., Nat. Commun., Nanoscale等重要学术期刊发表论文15 篇。担任多个国际著名学术期刊的审稿人（Chem. Sci., Nanoscale, Phys. Chem. Chem. Phys., ChemComm, J. Mater. Chem. C 等）。
