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arXiv · 1510.04402

Magnetization process of spin-1/2 Heisenberg antiferromagnets on a layered triangular lattice

Daisuke Yamamoto·Giacomo Marmorini·Ippei Danshita
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Abstract

We study the magnetization process of the spin-1/2 antiferromagnetic Heisenberg model on a layered triangular lattice by means of a numerical cluster mean-field method with a scaling scheme (CMF+S). It has been known that antiferromagnetic spins on a two-dimensional (2D) triangular lattice with quantum fluctuations exhibit a one-third magnetization plateau in the magnetization curve under magnetic field. We demonstrate that the CMF+S quantitatively reproduces the magnetization curve including the stabilization of the plateau. {We also discuss the effects of a finite interlayer coupling, which is unavoidable in real quasi-2D materials. It has been recently argued for a model of the layered-triangular-lattice compound Ba3CoSb2O9 that such interlayer coupling can induce an additional first-order transition at a strong field. We present the detailed CMF+S results for the magnetization and susceptibility curves of the fundamental Heisenberg Hamiltonian in the presence of magnetic field and weak antiferromagnetic interlayer coupling. The extra first-order transition appears as a quite small jump in the magnetization curve and a divergence in the susceptibility at a strong magnetic field ~ 0.712 of the saturation field.

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Daisuke Yamamoto, Giacomo Marmorini, Ippei Danshita. 2015-10-15. Magnetization process of spin-1/2 Heisenberg antiferromagnets on a layered triangular lattice. https://doi.org/10.7566/jpsj.85.024706

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