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.
Журнал: JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM
Выпуск журнала: Vol. 27, Is. 4
Номера страниц: 955-963
ISSN журнала: 15571939
Место издания: NEW YORK
Издатель: SPRINGER