Multiorbital cluster dynamical mean-field theory with an improved continuous-time quantum Monte Carlo algorithm

Yusuke Nomura, Shiro Sakai, Ryotaro Arita

Research output: Contribution to journalArticlepeer-review

20 Citations (Scopus)

Abstract

We implement a multiorbital cluster dynamical mean-field theory (DMFT) by improving a sample update algorithm in the continuous-time quantum Monte Carlo method based on the interaction expansion. The proposed sampling scheme for the spin-flip and pair-hopping interactions in the two-orbital systems mitigates the sign problem, giving an efficient way to deal with these interactions. In particular, in the single-site DMFT, we see that the negative signs vanish. We apply the method to the two-dimensional two-orbital Hubbard model at half-filling, where we take into account the short-range spatial correlation effects within a four-site cluster. We show that, compared to the single-site DMFT results, the critical interaction value for the metal-insulator transition decreases and that the effects of the spin-flip and pair-hopping terms are less significant in the parameter region we have studied. The present method provides a firm starting point for the study of intersite correlations in multiorbital systems. It also has a wide applicable scope in terms of realistic calculations in conjunction with density functional theory.

Original languageEnglish
Article number195146
JournalPhysical Review B - Condensed Matter and Materials Physics
Volume89
Issue number19
DOIs
Publication statusPublished - 2014 May 30
Externally publishedYes

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics

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