Dynamical structure factors of S=1 bond-alternating Heisenberg chains

Abstract

We calculate the dynamical structural factor of the S=1 bond-alternating Heisenberg chain. In the Haldane phase, the lowest excited states form the lower edge of the multimagnon continuum in $0\le q\le q_c$ and the one-magnon mode in $q_c\le q\le \pi$. As the system approaches the gapless point, $q_c$ shifts towards $q=\pi$ and the largest integrated intensity of the one-magnon mode is decreased. In the singlet-dimer phase, the one-magnon mode appears in $0\le q\le q_c$. As the bond-alternation becomes strong, $q_c$ shifts towards $q=\pi$. In the antiferromagnetic-ferromagnetic bond-alternation region with a strong ferromagnetic coupling, the lowest excited states form the lower edge of the multimagnon continuum in $0\le q\le 0.2\pi$ and $0.8\pi \le q\le \pi$, and the one-magnon mode appears in $0.2\pi <q<0.8\pi$. The largest integrated intensity of the one-magnon mode is 93%, which is slightly smaller than that in the S=1 Haldane-gap system. We further discuss the dynamical structural factor in connection with the inelastic neutron-scattering experiments.

6 pages, 3 figures

References in corpus (4)

• Order Parameter to Characterize Valence-Bond-Solid States in Quantum Spin Chains
• The properties of Haldane excitations and multi-particle states in the antiferromagnetic spin-1 chain compound CsNiCl
• Dynamical structure factors of the magnetization-plateau state in the $S=1/2$ bond-alternating spin chain with a next-nearest-neighbor interaction
• Dynamical structure factors of $S=1/2$ two-leg spin ladder systems

Cited by in corpus (3)

• Quantized excitation spectra by magnon confinement in quasi-one-dimensional S=1 spin systems
• Dynamical properties of S=1 bond-alternating Heisenberg chains in transverse magnetic fields
• Dynamical properties of S=1 bond-alternating Heisenberg chains at finite temperatures