1. Cluster-size dependence in cellular dynamical mean-field theory.
- Author
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Sakai, Shiro, Sangiovanni, Giorgio, Civelli, Marcello, Motome, Yukitoshi, Held, Karsten, and Imada, Masatoshi
- Subjects
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MEAN field theory , *HUBBARD model , *MOTT effect (Physics) , *QUANTUM theory , *MICROCLUSTERS , *MONTE Carlo method , *ELECTRIC insulators & insulation , *THERMODYNAMICS - Abstract
We examine the cluster-size dependence of the cellular dynamical mean-field theory (CDMFT) applied to the two-dimensional Hubbard model. Employing the continuous-time quantum Monte Carlo method as the solver for the effective cluster model, we obtain CDMFT solutions for 4-, 8-, 12-, and 16-site clusters at a low temperature. Comparing various periodization schemes, which are used to construct the infinite-lattice quantities from the cluster results, we find that the cumulant periodization yields the fastest convergence for the hole-doped Mott insulator where the most severe size dependence is expected. We also find that the convergence is much faster around (0.0) and (&pgr;/2,&pgr;/2) than around (&pgr;,0) and (&pgr;,&pgr;). The cumulant-periodized self-energy seems to be close to its thermodynamic limit already for a 16-site cluster in the range of parameters studied. The 4-site results remarkably agree well with the 16-site results, indicating that the previous studies based on the 4-site cluster capture the essence of the physics of doped Mott insulators. [ABSTRACT FROM AUTHOR]
- Published
- 2012
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