The two-state Bose-Hubbard model in the hard-core boson limit: Non-ergodicity and the Bose-Einstein condensation

被引：4

作者：

Stasyuk, I. V. ^{[1
]}

Velychko, O. V. ^{[1
]}

机构：

[1] Natl Acad Sci Ukraine, Inst Condensed Matter Phys, UA-79011 Lvov, Ukraine

来源：

CONDENSED MATTER PHYSICS | 2012年 / 15卷 / 03期

关键词：

Bose-Hubbard model; hard-core bosons; Bose-Einstein condensation; excited band; non-ergodicity; HYDROGEN; BAND; DELOCALIZATION; SUPERFLUID; DYNAMICS; SURFACES; PHONONS; FIELD;

D O I：

10.5488/CMP.15.33002

中图分类号：

O469 [凝聚态物理学];

学科分类号：

070205 ;

摘要：

The Bose-Einstein condensation in the hard-core boson limit (HCB) of the Bose-Hubbard model with two local states and the particle hopping in the excited band only is investigated. For the purpose of considering the non-ergodicity, a single-particle spectral density is calculated in the random phase approximation by means of the temperature boson Green functions. The non-ergodic contribution to the momentum distribution function of)articles (connected with the static density fluctuations) increases significantly and becomes comparable with the ergodic contribution in the superfluid phase near the tricritical point.

引用

页数：9

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