EAPSI: Investigating superconductivity in ultrathin materials

Jawdat Benmaan, Houston TX

Investigators

Abstract

A superconductor is a type of material that allows electricity to flow without any resistance. However, these materials have to be cooled down to low temperatures before they can exhibit this property. Superconductivity at room temperature would vastly improve many aspects of life; long distance power transmission, medical imaging, and transportation are just a few examples. This project will explore the possibility of superconductivity at the interface, or "meeting area", between different materials by employing a technique that allows for the growth of atomically smooth interfaces, called Molecular Beam Epitaxy (MBE). A specialized MBE for the growth of oxide materials will be used under the guidance of Dr. Wei-Li Lee at Academia Sinica in Taiwan. Molecular Beam Epitaxy is a technique that allows for atomic layer-by-layer growth of materials. This allows growth of novel materials that would otherwise be inaccessible by traditional solid state methods, as well as the observation of new phenomena that may not be present in bulk materials. Recently, interfacial superconductivity in thin film materials has gained great interest due to several observations of significantly elevated Tc. Materials thought to be superconducting via an interfacial mechanism include FeSe thin films, RE-doped CaFe2As2, the Sr2RuO4-Ru eutectic system, and LaAlO3/SrTiO3 (LAO/STO). In LAO/STO, superconductivity arises at the interface between two insulators. This project will probe the role of the interface by employing an oxide Molecular Beam Epitaxy (MBE) system to grow materials with a focus on the LAO / STO system. This project aims to characterize the crystal structures as well as the physical properties of the grown films in order to better understand the nature of the superconductivity in this system and others. This NSF EAPSI award is funded in collaboration with the National Science Council of Taiwan.