Uniform TitleOrbital selective Mott transition in 3d and 5f materials
NameToropova, Antonina (author), Kotliar, Gabriel (chair), Andrei, Natan (internal member), Chandra, Premala (internal member), Mekjian, Aram (internal member), Zhu, Jian-Xin (outside member), Rutgers University, Graduate School - New Brunswick,
SubjectPhysics and Astronomy,
DescriptionWe study two types of strongly correlated electron systems in the example of the transition oxide CrO2 and actinide series. We found
that the physics of both types of materials can be interpreted and discussed using concept of orbital selective Mott transition (OSMT). The theory of OSMT is discussed in framework of the
multiorbital Hubbard model applied to the description of t2g orbitals of Cr atoms in chromium dioxide as well as in the framework of a more generalized model for 5f materials
containing both Hubbard-like and Anderson-like contributions.
The electronic structure, transport, and magnetic properties of selected compounds are investigated by means of Ab Initio calculations. The many body techniques such as LDA+U and
dynamical mean field theory (DMFT) have been used in addition to density functional based local density approximation (LDA) method.
The half-metallic ferromagnet CrO2 has been shown to demonstrate effectively weakly correlated behavior in ordered state due to big
exchange splitting within t2g orbitals. The detailed DMFT study with Quantum Monte Carlo (QMC) impurity solver revealed that in the paramagnetic state this compound was on the edge of a quantum transition.
In the case of the actinide series we first demonstrated the choice of basis which optimum for DMFT based calculations. By
means of detailed one-electron band structure analysis we showed that hybridization term of 5f-orbitals with conduction electrons
must be included in the actinide Hamiltonian due to permanent presence of uncorrelated states at Fermi level. We conclude study
of 5f-materials presenting tight-binding parametrization and exploring magnetic characteristics.
NoteIncludes bibliographical references (p. 142-151).
CollectionGraduate School - New Brunswick Electronic Theses and Dissertations
Organization NameRutgers, The State University of New Jersey
RightsThe author owns the copyright to this work.