Complete phase diagram for the integrable chain with alternating spins in the sectors with competing interactions

Abstract

We investigate the anisotropic integrable spin chain consisting of spins $s=1/2$ and $s=1$ by means of thermodynamic Bethe ansatz for the anisotropy $\gamma >\pi /3$, where the analysis of the Takahashi conditions leads to a more complicated string picture. We give the phase diagram with respect to the two real coupling constants $\bar{c}$ and $\tilde{c}$, which contains a new region where the ground state is formed by strings with infinite Fermi zones. In this region the velocities of sound for the two physical excitations have been calculated from the dressed energies. This leads to an additional line of conformal invariance not known before.

13 pages, LaTeX, uses ioplppt.sty and epsfig.sty, figure 3 corrected

References in corpus (3)

• Ground State Structure and Low Temperature Behaviour of an Integrable Chain with Alternating Spins
• Ground state and low excitations of an integrable chain with alternating spins
• Finite-size corrections of an integrable chain with alternating spins

Cited by in corpus (3)

• Existence of the magnetization plateau in a class of exactly solvable Ising-Heisenberg chains
• Scattering matrix for a general gl(2) spin chain
• Dispersion relations and speeds of sound in special sectors for the integrable chain with alternating spins