Slave Boson Theory of Orbital Differentiation with Crystal Field Effects: Application to UO$_2$

ORAL

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 differention within the $5f$ manifold, with Mott localized $\Gamma_8$ and extended $\Gamma_7$ electrons.

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Authors

  • Nicola Lanata

    Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA

  • Yongxin Yao

    Ames Lab and Iowa State University, Ames Laboratory-U.S. DOE and Department of Physics and Astronomy, Iowa State University, Ames, Iowa IA 50011, USA

  • Xiaoyu Deng

    Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856-8019, USA

  • Vladimir Dobrosavljevi

    Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, Florida 32306, USA, Department of Physics and National High Magnetic Field Laboratory, Florida State University, Tallahassee, FL 32306, USA

  • Gabriel Kotliar

    Department of Physics and Astronomy, Rutgers University, Piscataway, NJ 08854, Department of Physics and Astronomy, Rutgers University, Piscataway, New Jersey 08856-8019, USA, Rutgers University, Center for Materials Theory, Rutgers University, Rutgers University, New Jersey, USA