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

Authors

Yongmin Yu, University of Rhode Island
Gerhard Müller, University of Rhode IslandFollow
V. S. Viswanath, University of Rhode Island

Document Type

Article

Date of Original Version

10-1-1996

Abstract

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 a weak-coupling continued-fraction analysis. The focus is on the dynamic structure factors S_zz(q,ω) and S_DD(q,ω), which describe (for q = π) the fluctuations of the Néel and dimer order parameters, respectively. We calculate the dependence on the exchange constants of the infrared exponent, the renormalized bandwidth of spinon excitations, and the spectral-weight distribution in S_zz(q,ω) and S_DD(π,ω), 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 Szz(π,ω) but not to SDD(q,ω).

Citation/Publisher Attribution

Yongmin Yu, Gerhard Müller, and V.S. Viswanath. Dimer and Néel order-parameter fluctuations in the spin-fluid phase of the s=1/2 spin chain with first and second neighbor couplings. Phys. Rev. B 54 (1996), 9242-9249.

Available at: http://dx.doi.org/10.1103/PhysRevB.54.9242

Publisher Statement

Copyright 1996 The American Physical Society.