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).