Probing interfaces in quantum materials where every atom counts

Mohammad Saghayezhian

Postdoctoral Researcher, LSU Department of Physics & Astronomy

Probing interfaces in quantum materials where every atom counts

Complex oxides are extremely sensitive to the changes in the local and extended crystal structure, as well as chemical composition, specially at their interface where two materials with different symmetries meet. Broken symmetry is a key player in the emergence of unexpected properties such as superconductivity, multi-ferroism and topological properties providing a viable platform for the next generation multi-functional quantum devices. A central factor in all their amazing properties is the structure, more specifically the structural symmetry, both at the interface and within the material. In this colloquium, Dr. Saghayezhian will discuss how we design and create atomically precise heterostructures, and how we characterize them on an atomic scale. He will showcase examples of how subtle changes in local structure and composition leads to unexpected properties, specifically to unusual magnetism. Local interface induced structural modifications can affect regions far from the interface, signifying the potential of interfacial couplings. Given our ability to determine the geometric structure with atomically resolved electron microscopy, he will discuss the challenge of determining the symmetry of the valence electrons at an interface.