Speaker: 陈震 (清华大学材料学院)

Time: November 15, 2022 10:00

Place: 理科楼C302

报告摘要：Improvements in electron microscopy have provided many new opportunities to explore multiple degrees of freedom in condensed matter physics, well beyond the lattice. Now, we can detect every electron scattered by a sample in both real and momentum space. Using these multidimensional data, we can retrieve the scattering potential of the sample [1], regardless of its nature, such as the electrostatic potential from atoms and magnetic field from spin or even quantum states. In this talk, I will show a successful inversion of the long-standing multiple scattering problem, which was established by H. Bethe in the 1920s. A direct outcome of this inversion is that atoms can be imaged at a resolution mainly limited by the lattice vibration [2]. This new technique also allows for precise measurements of the atomic displacements on a sub-pico-meter scale. I will show one typical example of subtle lattice distortions due to strong electron-lattice coupling in a correlated oxide [3]. I will also show that nanoscale topological spin textures can be imaged at a remarkably high sensitivity and resolution [4]. Finally, I will share my views on the impact of state-of-the-art electron microscopy in condensed matter physics.

References

[1] Y. Jiang#, Z. Chen#, et al., Nature 559, 343 (2018).

[2] Z. Chen, et al., Science 372, 826 (2021).

[3] Y. Zhang#, Y. Li#, Z. Chen#*, et al., under review.

[4] Z. Chen*, et al., Nat. Nanotechnol. 17, 1165 (2022).

报告人简介：2014年于中国科学院物理研究所获理学博士学位，之后于澳大利亚莫纳什大学和美国康奈尔大学做博士后研究，目前为清华大学材料学院北京电子显微镜中心副研究员。相关研究工作获得图像分辨率吉尼斯世界纪录和两院院士评选的2021年世界十大科技进展新闻。入选国家级人才青年项目（优先资助）、MIT Technology Review 2021年度中国区35位35岁以下创新人物，获得美国显微学会博士后奖。相关工作以第一作者或通讯作者发表在Nature、Science和Nature Nanotechnology等期刊上。