Tailoring interface-induced emergent phases in magnetic complex oxides with atomic precision

Developments in synthesis and characterizing artificially structured materials have greatly advanced the possibility to explore new quantum states of matter at heterointerfaces. Atomically resolved electron microscopy and spectroscopy has been shown to hold the key to identify the structural, compositional and electronic behavior across the interfaces with atomic precision. This is especially crucial for complex oxides system since subtle variation in order parameters will give rise to totally unexpected phenomena. In this talk, we show that via the combination of high quality growth, electron microscopy, magnetic/transport characterization and theory, one can make self-assembled and artificially designed interface-induced phases that are inaccessible in bulk counterparts. Examples include interface-induced multiferroism with reemergent magnetic & electronic characters [1]; interface-driven unusual magnetic response in self-assembled magnetic nanostructures etc. Through these examples, we will illustrate that structural /composition evolution and correlation at interface are the most essential ingredients and serve as the foundation on the discovery of these emergent phenomena. We will also suggest a few recipes on designing low dimensional materials with amendable functionalities. [1] Guo et al, Proc. Natl. Acad. Sci. U.S.A. 114, E5062 (2017)