NSF/DMR-BSF: Electronic Correlations and Disorder in Berry materials

Kent State University, Kent OH

Investigators

Abstract

NONTECHNICAL SUMMARY This award supports theoretical research aimed at investigating the origin of unusual thermodynamic and transport properties that have been observed in a variety of novel materials in which the electron-electron interaction is strong. Recent experimental results on these systems have highlighted the emerging conceptual challenges that arise due to the interplay between electron-electron interaction and disorder, and the need to develop new theoretical tools to address these challenges. The goal of this project is to confront some of these challenges by formulating new physical concepts, which are expected to lead to a deeper understanding of the unusual experimental findings. The PI and his students will study three classes of electronic systems: (i) Materials which have unconventional superconducting properties, (ii) Materials which undergo a metal-insulator transition in their bulk, while their surface states remain metallic, and (iii) Iron-based superconductors which allow for the coexistence of superconductivity and magnetism upon chemical doping. This award also supports the PI’s educational and outreach activities, which include (i) the training of graduate students in modern condensed matter physics, (ii) the creation of a comprehensive collection of problems on the topic of superconductivity suitable for advanced graduate students, (ii) translation of a book dedicated to the memory of physicist Lev Landau, and (iv) preparation of a set of presentations on the “Physics of Cycling” for members of the local road cycling club at Kent Free Public Library. TECHNICAL SUMMARY This award supports theoretical research aimed at developing a theory of correlated electronic systems with Berry curvature to account for the interplay between electron-electron interaction and disorder. The PI will use contemporary methods such as field theory of non-equilibrium systems, diagrammatic approach, and exact integrability to (i) investigate anomalous transport properties in unconventional superconductors, (ii) study the quantum interference effects due to an interplay between Coulomb interactions and disorder on the value of spin-Hall conductivity, and (iii) describe the effects of Coulomb interactions on short-time dynamics of the chiral d+id superconductors and the formation of spatial inhomogeneities. In addition, the PI will investigate the many-body instabilities in higher angular momentum topological materials and develop a quasiclassical approach for disordered multiband superconductors with competing ground states focusing on how quantum fluctuations affect their thermodynamic and transport properties. This award also supports the PI’s educational and outreach activities, which include (i) the training of graduate students in modern condensed matter physics, (ii) the creation of a comprehensive collection of problems on the topic of superconductivity suitable for advanced graduate students, (ii) translation of a book dedicated to the memory of physicist Lev Landau, and (iv) preparation of a set of presentations on the “Physics of Cycling” for members of the local road cycling club at Kent Free Public Library. This award reflects NSF's statutory mission and has been deemed worthy of support through evaluation using the Foundation's intellectual merit and broader impacts review criteria.