Low-Lying Excitations in the S=1 Antiferromagnetic Heisenberg Chain

Abstract

In order to confirm the picture of domain-wall excitations in the hidden antiferromagnetic order of the Haldane phase, the structure of the low-lying excitations in the S=1 antiferromagnetic Heisenberg chain is studied by a quantum Monte Carlo method. It is confirmed that there exists a finite energy gap between the first- and the second-excited states at $k=\pi$ as well as between the ground state and the first-excited state at $k=\pi$. In the thermodynamic limit, the second-excited state at $k=\pi$ is separated from the ground state by the gap which is three times as large as the Haldane gap. From the size dependences of the low-lying-excitation energies, the interactions between the elementary excitations in the excited states are concluded to be repulsive.

11 pages, 6 Postscript figures, RevTex (to appear in Phys. Lett. A)

References in corpus (3)

• Finite-lattice extrapolations for a Haldane gap antiferromagnet
• Excitation Spectrum of $S=1$ Antiferromagnetic Chains
• Solitonic excitations in the Haldane phase of a S=1 chain

Cited by in corpus (11)

• Elementary Excitations of Heisenberg Ferrimagnetic Spin Chains
• Intrinsic double-peak structure of the specific heat in low-dimensional quantum ferrimagnets
• Finite-Temperature Dynamics and Thermal Intraband Magnon Scattering in Haldane Spin-One Chains
• Modified spin-wave description of the nuclear spin relaxation in ferrimagnetic Heisenberg chains
• Quantized excitation spectra by magnon confinement in quasi-one-dimensional S=1 spin systems
• Spin dynamics of the anisotropic spin-1 antiferromagnetic chain at finite magnetic fields
• Infinite boundary conditions for response functions and limit cycles in iDMRG, demonstrated for bilinear-biquadratic spin-1 chains
• Transition to the Haldane phase driven by electron-electron correlations
• Nuclear Magnetic Relaxation in the Haldane-Gap Antiferromagnet Ni(C_2_H_8_N_2_)_2_NO_2_(ClO_4_)
• Topological Phase Transition in the Two-Leg Hubbard Model: Emergence of the Haldane Phase via Diagonal Hopping and Strong Interactions
• Quantized ΔS=2 Excitation Spectra by Confinement in an S=1 Spin Chain