Gaussian-basis Monte Carlo method for numerical study on ground states of itinerant and strongly correlated electron systems

Takeshi Aimi*, Masatoshi Imada

*この研究の対応する著者

研究成果: Article査読

32 被引用数 (Scopus)

抄録

We examine Gaussian-basis Monte Carlo (GBMC) method introduced by Corney and Drummond. This method is based on an expansion of the density-matrix operator ρ by means of the coherent Gaussian-type operator basis Λ and does not suffer from the minus sign problem. The original method, however, often fails in reproducing the true ground state and causes systematic errors of calculated physical quantities because the samples are often trapped in some metastable or symmetry broken states. To overcome this difficulty, we combine the quantum-number projection scheme proposed by Assaad, Werner, Corboz, Gull, and Troyer in conjunction with the importance sampling of the original GBMC method. This improvement allows us to carry out the importance sampling in the quantum-number-projected phase-space. Some comparisons with the previous quantum-number projection scheme indicate that, in our method, the convergence with the ground state is accelerated, which makes it possible to extend the applicability and widen the range of tractable parameters in the GBMC method. The present scheme offers an efficient practical way of computation for strongly correlated electron systems beyond the range of system sizes, interaction strengths and lattice structures tractable by other computational methods such as the quantum Monte Carlo method.

本文言語English
論文番号084709
ジャーナルjournal of the physical society of japan
76
8
DOI
出版ステータスPublished - 2007 8月
外部発表はい

ASJC Scopus subject areas

  • 物理学および天文学(全般)

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