Studies of Quantum Spin Ladders at T=0 and at High Temperatures by Series Expansions

Дата и время публикации : 1996-02-09T07:31:32Z

Авторы публикации и институты :
J. Oitmaa (University of NSW)
Rajiv R. P Singh (University of California)
Zheng Weihong (University of NSW)

Ссылка на журнал-издание: Physical Review B54, 1009(1996)
Коментарии к cтатье: RevTeX, 14 figures
Первичная категория: cond-mat

Все категории : cond-mat

Краткий обзор статьи: We have carried out extensive series studies, at T=0 and at high temperatures, of 2-chain and 3-chain spin-half ladder systems with antiferromagnetic intrachain and both antiferromagnetic and ferromagnetic interchain couplings. Our results confirm the existence of a gap in the 2-chain Heisenberg ladders for all non-zero values of the interchain couplings. Complete dispersion relations for the spin-wave excitations are computed. For 3-chain systems, our results are consistent with a gapless spectrum. We also calculate the uniform magnetic susceptibility and specific heat as a function of temperature. We find that as $Tto 0$, for the 2-chain system the uniform susceptibility goes rapidly to zero, whereas for the 3-chain system it approaches a finite value. These results are compared in detail with previous studies of finite systems.

Category: Physics