Cornell University, USA

报告摘要：

In the past decade, the energy resolution of electron energy loss spectroscopy (EELS) in scanning transmission electron microscopes has reached sub-10 meV. This allows probing low energy excitations including phonons and infrared plasmons with a Å-sized electron beam, bringing new opportunities for understanding the lattice and charge degrees of freedom in materials. In this talk, I will first present atomically resolved imaging of phonons at the FeSe/SrTiO₃ interface [1]. The phonon modes involved in the electron-phonon coupling are identified, providing new insight on the Tc-enhancement mechanism. The second part of the talk will be given to infrared plasmons in doped semiconductors. I will demonstrate probing local carrier density via the plasmons in EELS [2], and imaging the nanoscale electronic inhomogeneity in BaSnO₃ [3].

References:

[1] H. Yang, et al., Nature, 635, 332 (2024)

[2] H. Yang, et al., Phys. Rev. B, 102, 205427 (2020)

[3] H. Yang, et al., ACS Nano, 16, 18795 (2022)

报告人简介：

杨洪彬博士，于2015年获得兰州大学学士学位， 2021获得美国Rutgers University (New Brunswick)博士学位，导师为Eric Garfunkel、Philip E. Batson教授。2021至2024年在美国University of California, Irvine进行博士后研究，合作导师为Xiaoqing Pan教授。2024年4月至今在美国Cornell University应用物理系进行博士后研究，合作导师David A. Muller教授。主要研究内容为高空间、能量分辨率的透射电子显微镜学以及它在复杂氧化物和高温超导体中的应用。

邀请人：陈震 特聘研究员（82649878）

联系人：陈震 zhen.chen@iphy.ac.cn 010-82649878