title: Slave Boson Theory of Orbital Differentiation with Crystal Field Effects: Application to UO_{2}.
abstract: We derive an exact operatorial reformulation of the rotational invariant slave boson method, and we apply it to describe the orbital differentiation in strongly correlated electron systems starting from first principles. The approach enables us to treat strong electron correlations, spin-orbit coupling, and crystal field splittings on the same footing by exploiting the gauge invariance of the mean-field equations. We apply our theory to the archetypical nuclear fuel UO_{2} and show that the ground state of this system displays a pronounced orbital differentiation within the 5f manifold, with Mott-localized Γ_{8} and extended Γ_{7} electrons.
authors.forename: Nicola
authors.initials: N
authors.lastname: Lanatà
authors.forename: Yongxin
authors.initials: Y
authors.lastname: Yao
authors.affiliation: Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856-8019, USA.
authors.forename: Xiaoyu
authors.initials: X
authors.lastname: Deng
authors.affiliation: Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA.
authors.forename: Vladimir
authors.initials: V
authors.lastname: Dobrosavljević
authors.affiliation: Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856-8019, USA.|Condensed Matter Physics and Materials Science Department, Brookhaven National Laboratories, Upton, New York 11973-5000, USA.
authors.forename: Gabriel
authors.initials: G
authors.lastname: Kotliar