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Magnetic Double Structure for S=1, 1/2 Mixed-Spin Systems

Y. Takushima·A. Koga·N. Kawakami
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Abstract

We investigate the zero-temperature and the finite-temperature properties of the two-dimensional antiferromagnetic quantum spin system composed of the s=1/2 and s=1 spins. The spin excitation spectrum as well as the thermodynamic quantities are computed by means of the Schwinger-boson mean-field theory. We discuss how the magnetic double structure with the gapful and the gapless excitations is generated, and apply the results systematically to the Haldane gap system in a staggered magnetic field and also to the weakly coupled ferrimagnetic mixed-spin chains. It is confirmed that the results obtained are consistent with the experiments for the quasi-one-dimensional Haldane compounds $R_2 \rm BaNiO_5$.

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Y. Takushima, A. Koga, N. Kawakami. 2000-03-15. Magnetic Double Structure for S=1, 1/2 Mixed-Spin Systems. https://doi.org/10.1103/physrevb.61.15189

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