****Technical Abstract**** This project focuses on spin-orbit coupled systems where correlations are relevant. While there have been many recent theoretical studies describing novel phases in such materials, none of the intriguing predictions such as the Weyl semi-metal state or axion insulators has as yet been experimentally observed. Low temperature scanning tunneling microscopy (STM) is one of the best methods to probe the electronic structure of complex materials, which often exhibit nanoscale inhomogeneities. STM will be used to study correlated spin-orbit materials such as the pyrochlore and Ruddlesden-Popper series of iridates, or the Heusler compounds. Progress in understanding fundamental properties of these systems may lead to new paradigms in spin-orbit coupled complex systems. With close feedback from theory collaborators and quick turn around in obtaining single crystal and thin film samples, the group will rapidly be able to explore a variety of materials in search of novel phases. The integrated education activities include a new structured department-wide mentoring plan for post-docs, and involvement of undergraduates in research, which will help train the next generation of scientists, as well as an ongoing outreach program through the School of Education, which will have a measurable impact on the numbers of trained science teachers in middle- and high schools.
A new and exciting frontier in the exploring the physics of electrons and atoms in solids is the exploration of materials where there is more than one dominating interaction. Spin-orbit coupling is an interaction between the quantum mechanical spin of an electron and its orbital properties. When spin-orbit interaction is strong, materials are known to show novel effects. However, adding electron-electron interactions to these systems can vastly expand the range of novel properties. While there have been many recent theoretical studies on the possible new states in such materials, very few experimental studies have been carried out so far. Moreover, none of the intriguing predicted phases has as yet been experimentally observed. This project focuses on the fundamental physics of materials where with multiple interactions, which can either compete or aid one another. To study these materials we will use the tool of scanning tunneling microscopy, which has the power to not only image single atoms but also to move individual atoms to build artificial atomic scale structures. Any discoveries of novel states and understanding their properties will be vital to advancing our knowledge in this new field. This project will support graduate students and post-docs who will learn experimental techniques and the physics of materials at the cutting edge of current research.
