Magnetization Process of (S=3/2, S=1) Anisotropic Ferrimagnetic Spin Chain(Low Dimensional Systems, Field-Induced Phase Transitions and Dynamics in Quantum Spin Systems)

概要

論文の詳細を見る
Magnetization process of (S=3/2, S=1) ferrimagnetic spin chain with single-ion anisotropy D is investigated by numerical diagonalization. The magnetization process has a plateau at 1/5 of the saturation moment in the small D region. We find a quantum phase transition that the plateau once vanishes at a critical D and revives in the large D region. The critical value D_c is estimated to be 0.9. In order to clarify the mechanism of this transition, we propose new trial states : a pentamer state in the small D phase and a trimer state in the large D phase. We find that representative ground state is changed from the pentamer state to the trimer one, while D increases across D_c. This result suggests that the mechanism of the quantum phase transition is understood as the change of the representative ground state.
理論物理学刊行会の論文
2005-10-31