Inhomogeneous disorder Dirac Fermions: from heavy fermion superconductors to graphene. Final report

Vekhter, Ilya¹ 

[1] Louisiana State University

关键词: superconductivity;    correlated electrons;    heavy-fermion materials;    pnictide superconductors;   

DOI  :  10.2172/1089679
RP-ID  :  DOE/ER/46492-1
PID  :  OSTI ID: 1089679

学科分类：凝聚态物理

美国|英语

来源: SciTech Connect

【 摘 要 】

This is the final report on the award designed to foster a partnership between Louisiana State University and Los Alamos National Laboratory (LANL) in conducting fundamental research in support of energy needs. The general focus of the research effort was on developing a better understanding of materials with new functionalities. We investigated two distinct and very promising classes of new materials, which serve as a testing ground for many of the novel phenomena in condensed matter physics: the heavy fermion 115 series, where the interplay of strong interactions between the electrons leads to a rich variety of competing phases and anomalous properties, and newly discovered pnictide superconductors. The former focus was planned; the latter emerged during the collaborative effort with LANL. Our objective was to determine the origin, and to establish a functional effective theory description of the phases in these systems, and transitions between them. We report on the main accomplishments under the award that serves to clarify the nature of superconductivity in both families of materials. In particular, we collaborated with experimentalists to predict and analyze the magnetic field and temperature dependence of the bulk thermodynamic and transport properties and to determine the gap shape in CeCoIn??? and in Ba(Fe_1-xCo_x)???As???, investigated the Kondo temperature in the presence of spin-orbit coupling in the conduction band, and provided theoretical guidance for local probes such as scanning tunneling spectroscopy of vortex cores and impurity resonances, and magnetic force microscopy of the superconducting states.