Cryogenic Electron Microscopy of Electronic Order in Oxides

In correlated oxides, quantum-mechanical effects and strong electron-electron interactions give rise to superb electronic properties and a vast potential for future technologies. In these materials, electrons may self-organize into new spatial patterns that break the symmetry of the underlying crystal. These electron ordered states display a rich interplay between distinct degrees of freedom and may induce novel functionalities through the breaking of additional crystal symmetries. I will show vivid atomic-scale visualizations of electronic order enabled by the development of cryogenic capabilities (near 100 K) for scanning transmission electron microscopy. These measurements are combined with advanced analysis tools to reveal picoscale atomic displacements governing electronic transitions, the nature and symmetry of electronic order at the local scale, and nanoscale fluctuations that underlie macroscopic properties. Despite these advances, a persistent challenge in the field of cryogenic transmission electron microscopy is the lack of stable liquid-helium-cooled sample conditions. I will discuss recent developments that provide access to ultra-low temperatures, as low as 20 Kelvin, while maintaining atomic-resolution imaging performance, paving the way for broader explorations of ultra-low temperature phenomena in oxide and beyond.