CAREER: Neutron and X-Ray Scattering Studies of Unconventional Phase Transitions in Materials with Strong Interactions or Fluctuations

Massachusetts Institute Of Technology, Cambridge MA

Investigators

Abstract

The goal of this Faculty Early Career Development (CAREER) project at the Massachusetts Institute of Technology is to investigate the unconventional electronic and magnetic phases found in strongly correlated electron materials. Quantum effects play a central role in the many-body states, and unconventional phases may result (such as high-Tc superconductivity and disordered spin-liquids). This project will involve the synthesis of important materials, including copper-oxide superconductors and geometrically frustrated magnets, in clean, single-crystalline form. Neutron and x-ray scattering experiments will be performed at the national scattering facilities to provide unique information regarding nanoscale inhomogeneities and fluctuations of the charge, spin, and lattice degrees of freedom of the low-temperature phases. These measurements should help identify the relevant competing order parameters in these highly correlated systems, a topic of much current debate. The ultimate goal is to understand the basic structure of the many-body ground states, as well as create new materials that exhibit new phenomena. This project will naturally train future scientists to fully utilize the nation's investment in neutron and synchrotron x-ray scattering facilities. At MIT, a course will be taught to materials researchers on cutting-edge scattering techniques. Also, new visualization tools will be created to aid the teaching of quantum mechanics to undergraduates, and these will be used in outreach programs to local high-school students. Our understanding of the electronic behavior of materials is deficient. Current theory cannot describe the properties of systems composed of many quantum particles (such as electrons) that strongly interact with each other. Technologically useful properties may emerge within these systems, such as high temperature superconductivity and colossal magnetoresistance; however, the mechanisms that lead to these properties are not understood. The goal of this Faculty Early Career Development (CAREER) project at the Massachusetts Institute of Technology is to investigate the unconventional electronic and magnetic phases found in strongly interacting electron materials. This project will involve the synthesis of new materials, as well as studying them with scattering techniques. Neutrons and x-rays can scatter from the spin and charge of an electron, and thus can provide unique information regarding the collective behavior of the electrons in these systems. The ultimate goal is to understand the basic physics behind the emergent many-body phenomena, as well as discover new phenomena. This project will naturally train future scientists to fully utilize the nation's investment in large scattering facilities. At MIT, a course will be taught to materials researchers on cutting-edge scattering techniques. Also, new visualization tools will be created to aid the teaching of quantum mechanics to undergraduates, and these will be used in outreach programs to local high-school students.