Numerical calculation on low-energy magnetic excitations and its optical properties in multi-sublattices low-dimensional antiferromagnetic systems

Abstract

It was pointed out that the interaction of two magnons play an important role to express the exchange scattering in Raman spectra, and that the role of magnon should be modified depending on the effects of quantum spins and frustration. The calculated Raman spectra in triangular antiferromagnetic systems with spin-1/2 and -1 have been discussed. It was indicated that the above numerical reproduction has given the exact expression on the exchange scattering under the condition that the system is composed of finite spin sites. The Hamiltonian was described for the model with the anisotropic Heisenberg-type exchange interactions. The expression to calculate Raman spectra and the term of the interaction Hamiltonian were described. Numerical calculation has been made for systems of N = 27 with spin-1/2, and the results were shown in a figure. The spectra for exchange scattering in the E(sub 2g)(x(exp 2) - y(exp 2)) configuration for the system with spin-1/2 have been calculated and the results were shown in a figure. The behavior of systems between Ising and Heisenberg models, and the ground state of Ising antiferromagnetism have been discussed referring to the previous papers.

ラマンスペクトルにおける交換散乱を表現するのに、2つのマグノンの相互作用が重要な役割を果たすこと、および量子スピンとフラストレーションの影響次第では、マグノンの役割を変更する必要があることを指摘した。スピン-1/2およびスピン-1を有する3角反強磁性系のラマンスペクトルの計算結果を論じた。上記の数値的再現が、有限スピンサイトから構成される系という条件下での交換散乱に対し厳密な式をもたらすことを指摘した。異方性ハイゼンベルク型交換相互作用を有する模型についてハミルトニアンを記述した。ラマンスペクトルの計算式と相互作用ハミルトニアンの項を記述した。スピン-1/2をもつN=27の系について数値計算を行い、結果を図示した。スピン-1/2の系について、E(sub 2g)(x(exp 2)-y(exp 2))配置の交換散乱に対するスペクトルを計算し、結果を図示した。イジング模型とハイゼンベルク模型との間の系の挙動、およびイジング反強磁性の基底状態を既報論文を引用して論じた。