A Gutzwiller study of correlated multi-orbital systems

DIPC Seminars

Bo Hellsing, University of Gothenburg, Sweden
Donostia International Physics Center (DIPC).Paseo Manuel de Lardizabal, 4 (nearby the Facultad de Quimica), Donostia
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A Gutzwiller study of correlated multi-orbital systems **A Gutzwiller study of correlated multi-orbital systems ** Nicola Lanata 1, Hugo U. R. Strand 1, Xi Dai 2 and Bo Hellsing 1 1\. University of Gothenburg, SE-412 96 Gothenburg, Sweden 2\. Beijing National Laboratory for Condensed Matter Physics and Institute of Physics, Chinese Academy of Sciences, Beijing 100190, China We present a numerical method to minimize the general multi-orbital Gutzwiller variational wave functions [1]. The method can treat any type of local interaction, in particular spin-flip and pair-hopping interactions. To construct the variational wave function, we apply the phi-matrix formalism [2] and a general approach to reduce the variational space by imposing lattice point group symmetries. Results for the multi-orbital Hubbard model of d-electron systems with rotational invariant Kanamori interaction will be demonstrated. The variational wave function is restricted to cubic symmetry. Properties of the model is studied as a function of N (total number of electrons), D ï€ (eg-t2g crystal field splitting), U (interaction strength) and J (spin-exchange coupling). Our numerical results for the quasi-particle weight, Z vs U and the phase diagram, J/U vs Uc, indicate dramatic changes when going off halffilling (N=5). [1] N. Lanata, H.U.R. Strand, X. Dai, B. Hellsing, Phys Rev B 85, 035133-1 (2012) [2] N. Lanata, P. Barone, M. Fabrizio, Phys. Rev. B 78, 155127 (2008