Abstract
The debate whether uranium electrons are closer to being localized or itinerant in the ferromagnetic compound is not yet fully settled. The experimentally determined magnetic moments are large, approximately , suggesting the localized character of the electrons. In the same time, one can identify signs of itinerant as well as localized behavior in various spectroscopic observations. The band theory, employing local exchange-correlation functionals, is biased toward itinerant states and severely underestimates the moments. Using material-specific dynamical mean-field theory (DMFT), we probe how a less approximate description of electron-electron correlations improves the picture. We present two variants of the theory: starting either from spin-restricted (LDA) or spin-polarized (LSDA) band structure. We show that the L(S) method can accurately describe the magnetic moments in as long as the exchange interaction between the uranium and electrons is preserved by a judicious choice of the spin-polarized double-counting correction. We discuss the computed electronic structure in relation to photoemission experiments and show how the correlations reduce the Sommerfeld coefficient of the electronic specific heat by shifting the states slightly away from the Fermi level.
5 More- Received 18 February 2021
- Revised 30 April 2021
- Accepted 7 May 2021
DOI:https://doi.org/10.1103/PhysRevB.103.205146
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