On the nature of the absolute maximal observable magneto-optical Kerr rotation of CeSb

Max-Planck Research Group "Theory of Complex and Correlated Electron Systems”, University of Technology - D-01062 Dresden, Germany

Received: 25 April 1996
Accepted: 14 October 1996

Abstract

We report first-principles calculations of the polar magneto-optical (MO) Kerr spectra of the Ce compounds CeSb, , CeTe, and CeSe, using the local-density approximation (LDA) of density-functional theory as well as its generalization which contains an explicit Coulomb interaction U (LDA+U). Although the LDA predicts a large Kerr rotation of about 20 in CeSb, we find that the LDA+U gives a better description of the Kerr spectra of all four compounds. For CeSb the LDA+U predicts a colossal Kerr rotation of 45 up to 60, in agreement with the recent discovery of the maximal observable rotation of 90 in CeSb by Pittini et al. (Phys. Rev. Lett., 77 (1996) 944). The origin of the colossal Kerr rotation realized in CeSb is examined.