Cluster Size and Shape Effect on the Electronic Structure of the Hubbard Model Within the Norm-Conserving Cluster Perturbation Theory


Тип публикации: статья из журнала

Год издания: 2014

Идентификатор DOI: 10.1007/s10948-013-2418-7

Ключевые слова: Cluster perturbation theory, Hubbard model, Strong correlations, Density of states, Fermi surface, Electronic structure, Phase transitions, Cluster perturbation theories, Density of state, Quantum monte carlo, Quantum phase transitions, Quasi particles, Spectral weight, Strong correlation, Surface transforms

Аннотация: Within a new norm-conserving approach to the cluster perturbation theory (CPT) for the 2d Hubbard model we study the effect of the cluster size and shape on the electronic structure. We have compared two type of clusters, 4-cluster (2x2) and 5-cluster (cruciform of 5 atoms). With 4-cluster we can treat exactly the first and second Показать полностьюneighbours correlations, C (1) and C (2). With 5-cluster the third neighbour correlations C (3) are also treated exactly. The band structure in the CPT with 4- and 5-clusters differs remarkably. The quasiparticle spectral weight map for 5-clusters is very similar to the Quantum Monte Carlo (QMC) and the variational CPT data. With increasing doping, small hole Fermi surface transforms into conventional Fermi-liquid type large Fermi surface through Lifshitz quantum phase transitions.

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Выпуск журнала: Vol. 27, Is. 4

Номера страниц: 955-963

ISSN журнала: 15571939

Место издания: NEW YORK

Издатель: SPRINGER


  • Krinitsyn A. (Dostoyevsky Omsk State University)
  • Nikolaev S. (Siberian Federal University)
  • Ovchinnikov S. (Kirensky Institute of Physics, Siberian Branch, Russian Academy of Sciences)