The modern theory of materials, based on the quantum theory of solids and powerful computational methods, makes it possible to apply the theoretical concepts to realistic situations. This allows researchers to explain experimental findings in great detail, as well as to make predictions about possible new structures and materials with interesting behavior. Our group explores these possibilities for applications to important scientific questions, like the microscopic origin of complex phenomena in materials, for example, the brittle-to-ductile transition in solids. We are also interested in using these theoretical tools to address societal needs, such as the development of novel materials for efficient solar energy conversion or for better energy storage devices, as well as problems related to biomolecules, like DNA, and their interaction with materials such as carbon nanotubes and graphene. All these research topics can lead to better understanding of fundamental issues in the behavior of materials, or to solutions for practical problems in energy and biomedical applications.
Abstract:
Electronic structure and correlations in twisted multilayer graphene and other layered materials
In the past few years, the field of twisted multilayer graphene and other layered materials like the transition-metal dichalcogenide family, has blossomed to the point of being referred with its own term, "twistronics". New structures, including twisted n-layers (n=3,4,...), mixed layers, and multilayers of regular multilayers, are being studied experimentally and revealing ever richer behavior. We discuss theoretical investigations of some representative systems, starting with the iconic twisted bilayer graphene near the magic angle. Our work is based on first-principles tight-biding hamiltonians and includes atomic relaxation. We focus on the realistic representation of single-particle states and how those can be employed in studying many-body physics related to Mott insulator behavior, superconductivity and other manifestations of correlated electronic states.
