Dimer and Néel order-parameter fluctuations in the spin-fluid phase of the s=1/2 spin chain with first and second neighbor couplings

Дата и время публикации : 1996-04-11T13:55:09Z

Авторы публикации и институты :
Yongmin Yu (University of Rhode Island)
Gerhard Müller (University of Rhode Island)
V. S. Viswanath (Oak Ridge National Laboratory)

Ссылка на журнал-издание: Ссылка на журнал-издание не найдена
Коментарии к cтатье: RevTex file (7 pages), 8 figures (uuencoded ps file) available from authors
Первичная категория: cond-mat

Все категории : cond-mat

Краткий обзор статьи: The dynamical properties at T=0 of the one-dimensional (1D) s=1/2 nearest-neighbor (nn) XXZ model with an additional isotropic next-nearest-neighbor (nnn) coupling are investigated by means of the recursion method in combination with techniques of continued-fraction analysis. The focus is on the dynamic structure factors S_{zz}(q,omega) and S_{DD}(q,omega), which describe (for q=pi) the fluctuations of the N’eel and dimer order parameters, respectively. We calculate (via weak-coupling continued-fraction analysis) the dependence on the exchange constants of the infrared exponent, the renormalized bandwidth of spinon excitations, and the spectral-weight distribution in S_{zz}(pi,omega) and S_{DD}(pi,omega), all in the spin-fluid phase, which is realized for planar $nn$ anisotropy and sufficiently weak nnn coupling. For some parameter values we find a discrete branch of excitations above the spinon continuum. They contribute to S_{zz}(q,omega) but not to S_{DD}(q,omega).

Category: Physics