Novel Quantum Effects in Strongly Correlated Materials

University Of Oklahoma Norman Campus, Norman OK

Investigators

Abstract

NONTECHNICAL SUMMARY This award supports research and educational activities with an aim to understand and predict novel phases of matter in quantum materials, physical systems with a large number of particles where the laws of quantum mechanics are more prominently manifested. The PI will investigate metals where electrons can behave in very odd ways: In some cases they propagate as if they have no mass when they move in certain directions in space; in others, they move in a completely incoherent fashion, reaching thermal equilibrium at extremely fast time scales, unlike in conventional metals like copper or aluminum. As they propagate in materials, electrons can form phases of quantum matter with the most diverse properties. The way the electrons interact with each other can lead to novel states of matter; from metals that fail to conduct electricity to superconductors that conduct electricity without any dissipation of heat, or even regimes where electrons flow like a turbulent stream of water. The theoretical advances in this project will enhance the understanding of such phases of matter, and may lead to future device technologies and applications. This award also supports the PI's outreach activities to undergraduate students through the NSF Research Experience for Undergraduates program at the University of Oklahoma and to high school physics teachers in the metropolitan area of Oklahoma City through the NSF Research Experience for Teachers program. The PI will also enroll in the mentorship program at the Oklahoma School of Science and Mathematics, the premier public residential high school in the state of Oklahoma focused on Science, Technology, Engineering, and Mathematics disciplines, and will offer open lectures about science to the general public. TECHNICAL SUMMARY This award supports research and educational activities with an aim to enhance our fundamental understanding about interactions and novel quantum effects in a broad class of strongly correlated systems that host unconventional quasiparticles or where the concept of quasiparticles is entirely absent. The research will be focused on two main thrusts: 1) Correlations in unconventional metals, where PI will explore novel quantum critical phenomena and hydrodynamic behavior in systems with nodal-line semimetals and systems with semi-Dirac fermions, and the physics of incoherent metals and their possible relation to strange metal phases in various strongly correlated electron systems. 2) Many-body effects in Moire heterostructures, where the PI will theoretically examine the physics of interactions in twisted graphene bilayers at or near the magic angle, where superconductivity and correlated insulating behavior have been experimentally observed. The research team will investigate novel nematic superconducting phases emerging in the vicinity of quantum critical points, generalizations of the Sachdev-Ye-Kitaev model, the nature of strange metal phases from the point of view of experimental response functions, and the magnetic and correlated metallic phases observed in twisted graphene bilayers. This award also supports the PI's outreach activities to undergraduate students through the NSF Research Experience for Undergraduates program at the University of Oklahoma and to high school physics teachers in the metropolitan area of Oklahoma City through the NSF Research Experience for Teachers program. The PI will also enroll in the mentorship program at the Oklahoma School of Science and Mathematics, the premier public residential STEM high school in the state of Oklahoma, and will offer open lectures about science to the general public. 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.