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Spin-Peierls transition of the first order in S=1 antiferromagnetic Heisenberg chains

Hiroaki Onishi·Seiji Miyashita
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Abstract

We investigate a one-dimensional S=1 antiferromagnetic Heisenberg model coupled to a lattice distortion by a quantum Monte Carlo method. Investigating the ground state energy of the static bond-alternating chain, we find that the instability to a dimerized chain depends on the value of the spin-phonon coupling, unlike the case of S=1/2. The spin state is the dimer state or the uniform Haldane state depending on whether the lattice distorts or not, respectively. At an intermediate value of the spin-phonon coupling, we find the first-order transition between the two states. We also find the coexistence of the two states.

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Hiroaki Onishi, Seiji Miyashita. 2001-09-01. Spin-Peierls transition of the first order in S=1 antiferromagnetic Heisenberg chains. https://doi.org/10.1103/physrevb.64.014405

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