Non-technical abstract: This award from the Condensed Matter Physics Program of the Division of Materials Research to the University of Virginia supports neutron scattering studies of novel superconductors to investigate the intricate interaction of disorder and superconductivity, and to probe the nature of the microscopic interactions at the smallest scale possible. Superconductivity is the state of matter characterized by zero electrical resistance. Materials carrying this property can potentially mitigate some of the world's energy challenges and transportation demands in the future. Since its initial discovery about 100 years ago, many superconductors have been synthesized in the laboratory leading to discoveries of very complex phenomena. In 1957, Bardeen Cooper and Schrieffer developed a theory that explains adequately the mechanism that leads to superconductivity in simple metals. Nowadays, superconductivity has been found in materials that are far from simple metals and the objective of this project is to provide data to help with theoretical understanding of their unconventional properties and mechanisms. The broader impact is to train future generation of scientists who, using sophisticated characterization techniques, will contribute to important areas of physics.
This award from the Condensed Matter Physics Program of the Division of Materials Research supports the University of Virginia on a collaborative study of new classes of superconductors, based on BiS2 building blocks. These materials exhibit strong coupling of the structure to superconducting transition temperature. The investigators manipulate the crystal chemistry of the materials to tune the ground state between insulating, semiconducting or metallic, non-magnetic or magnetic states. Scattering techniques (neutrons) including pair density function (PDF) techniques are used to study the structural and magnetic properties. The investigators have complementary expertise in local atomic structure, phonon and magnetic dynamics characterization. The objective of this comprehensive approach is to shed light on pairing mechanisms, and generate phonon/magnetic excitations data for theoretical simulations.