Experimental Study of New Universality Classes in Magnetic Phase Transition

磁相变新普适类的实验研究

• 批准号: 05640409
• 负责人: AJIRO Yoshitami
• 金额: $ 1.22万
• 依托单位: FUKUI UNIVERSITY
• 依托单位国家: 日本
• 项目类别: Grant-in-Aid for General Scientific Research (C)
• 财政年份: 1993
• 资助国家: 日本
• 起止时间: 1993 至 1994
• 项目状态: 已结题
• 来源: https://kaken.nii.ac.jp/en/grant/KAKENHI-PROJECT-05640409/
• 关键词: Phase transition; Universality; Phase diagram; Triangular lattice; One-dimensional magnet; Quantum spin; 磁気相転移; 三角格子反強磁性体

The purpose of the present research is to elucidate the phase transitions in low dimensional magnetic system, such as frustrated triangular lattice antiferromagnet and quantum spin one-dimensional antiferromagnet.We performed the experimental study on various model substances using nuclear magnetic resonance (NMR), electron spin resonance (ESR), neutron scattering, susceptibity and high field magnetization maeasuments.1.Triangular lattice antiferromagnetOur precise measurements between 1.4K and 300K under static magnetic fields up to 40 T,occasionally up to 110 T,revealed a rich variety of magnetic phase transitions in the stacked triangular lattice antiferromagnets ABX3 and AMO2, including a novel phase transition which belongs to a new universality class linked to chiral degeneracy.The magnetic field versus temoerature phase diagrams are classified into two types depending on their magnetic antisotropies.2.Quantum spin systemNonmagnetic groud states due to quantum spin effect were studied for one-dimensional Heisenberg systems.We observed remarkable differneces in the nonmagnetic impurity efect on the Haldane system, spin-Peierls system and alternating linear chain system and disscussed the physical sihnificance of the results.

为了阐明低维磁性系统中的相变，如阻挫三角晶格反铁磁体和量子自旋一维反铁磁体，我们利用核磁共振（NMR）、电子自旋共振（ESR）、中子散射、在1.4K和300 K之间，在高达40 T的静磁场下，偶尔高达110 T，揭示了在堆叠的三角晶格反铁磁体ABX 3和AMO 2中的丰富多样的磁相变，其中包括一个新的相变，它属于与手征简并有关的一个新的普适类.根据它们的磁各向异性，磁场-温度相图可分为两种类型. 2.量子自旋系统研究了单自旋系统中由量子自旋效应引起的非磁基态.我们观察到在Haldinger系统、spin-Peierls系统和交替线性链系统中，电子杂质效应的显著差异，并讨论了结果的物理意义。

项目成果

M.Chiba: "Anomalous Spectrum of ^<133>Cs NMR in CsCuCl_3 around the Applied Field 11T" J.Phys.Soc.Jpn.62. 4186-4189 (1993)

M.Chiba：“应用场11T周围CsCuCl_3中^ 133 Cs NMR的反常谱”J.Phys.Soc.Jpn.62。

Y.Ajiro: "High Field Magnetization Process in Triangular Lattice Antiferromagnet CuFeO_2" Physica B. 201. 71-74 (1994)

Y.Ajiro：“三角晶格反铁磁体 CuFeO_2 中的高场磁化过程”Physica B. 201. 71-74 (1994)

Y.Ajiro: "High Field Magnetization of a One-Dinensional S=1/2 Trimer System 3CuCl_2,2dioxare" J.Phys.Soc.Jpn.63. 859-862 (1994)

Y.Ajiro：“一维 S=1/2 三聚体系统 3CuCl_2,2dioxare 的高场磁化”J.Phys.Soc.Jpn.63。

Y.Ajiro, T.Asano, T.Takagi, M.Mekata, H.Katori, T.Goto: "High Field Magnetization Process in Triangular Lattice Antiferromagnet CuFe02" Physica B. 201. 71-74 (1994)

Y.Ajiro、T.Asano、T.Takagi、M.Mekata、H.Katori、T.Goto：“三角晶格反铁磁体 CuFe02 中的高场磁化过程”Physica B. 201. 71-74 (1994)

M.Chiba, Y.Ajiro, T.Morimoto: "NMR Study on the Quantum Spin Effect on the One-Dimensional Magnet in High Magnetic Fields" Physica B. 201. 200-203 (1994)

M.Chiba、Y.Ajiro、T.Morimoto：“高磁场中一维磁体的量子自旋效应的核磁共振研究”Physica B. 201. 200-203 (1994)