CAREER: Exploring Artificial Quantum Matter

Technical:

The goal of this project is to create, characterize and control novel quantum states of condensed matter at the interfaces of complex oxide materials using atomic layer-by-layer synthesis and recently pioneered methodologies for advanced characterization with synchrotron radiation. The astounding advances in the science and technology of semiconductor heterostructures have been made possible by three fundamental achievements: The density of the electron system at the interface can be effectively tuned by virtue of band structure engineering; the mobility of charge carriers doped into interface states which exceeds the bulk mobility by orders of magnitude; and the carriers which can channel into patterned devices along the interface. All three conditions have recently been replicated in heterostructures of complex transition metal oxides. As complex oxide materials exhibit a remarkably rich phase behavior in the bulk, quantum states with properties and functionalities beyond those attainable in semiconductors are expected to emerge in the interface-controlled oxides. Based on this, the project to fabricate, explore and thoroughly understand new quantum phenomena that arise at the oxide interfaces due to nanoscale effects and artificially broken symmetries is proposed. Using the atomic layer-by-layer synthesis the physics at the interface between non-Fermi liquid correlated metals and Mott insulators will be explored. Quantum coherence in the systems where interfacial magnetism and high-Tc superconductivity can co-exist will be investigated. Recently predicted new quantum phenomena such as exotic magnetic states and orbital reconstruction at the superconductor/ferromagnet interface will be sought out. New artificial quantum crystals that are tailored for properties not attainable in the bulk will be fabricated and explored. For this purpose, resonant soft X-ray spectroscopies and polarized neutrons at major national facilities and international centers of excellence will be utilized. Based on this proposal, a new graduate course in experimental methods for nanoscience and a new outreach summer program - 'Nano-Camp' will be specifically developed for underrepresented students and minorities across Arkansas. The proposed research will be used as a hub for the popular NSF GK-12 and REU programs.

Non-Technical:

Modern achievements in microelectronics rely on the properties of interfaces between two different semiconductors and the knowledge about electronic phenomena near semiconductor interfaces. Recent advances in the growth of oxides now allow for the formation of sharp boundaries between the atomic layers of complex oxides materials. Given the rich properties in the bulk of these compounds due to strong interactions between the electrons, the new interface quantum states promise the opportunity to uncover unexpected phenomena. The goal of this project is to fabricate and explore what are called artificial quantum materials with engineered physical properties not attainable in the bulk. X-rays synchrotron radiation that scatters from the spin, charge and orbit of an electron will provide unique knowledge about the behavior of the electrons at the interfaces. Understanding and manipulating these properties will open a path towards a new generation of oxide based electronic devices. Based on this proposal, a new graduate course in experimental methods for nanoscience and a new outreach summer program - 'Nano-Camp' will be specifically developed for underrepresented students and minorities across Arkansas. This project will also serve as a hub for stocking the emerging field with future scientists and engineers and will help to maintain a competitive presence in science and technology.