发表机构
Department of Nuclear and Particle Physics, Faculty of Physics, National and Kapodistrian University of Athens（雅典国立卡波蒂斯坦大学物理学院核与粒子物理系）
机构由 AI 辅助整理，请以论文原文为准。AI 中文总结
该研究针对含任意数量磁活性原子的链状磁体，用平均场方法推导其热力学，发现其相结构随耦合强度变化，长链的磁化态对应扭结孤子，还分析了端杂质引发的边界态。
AI 中文摘要
我们研究由链状构型的分子构成的磁体，这些分子包含任意数量$m$个磁活性原子，且通过近邻耦合相互作用。我们采用平均场方法推导了自旋为$j$的$SU(2)$磁性原子链的热力学，并确定了平衡态与稳定性条件。该系统呈现出丰富的相结构，包含一系列铁磁相变，其数量取决于耦合的相对强度，范围从最大铁磁体的$m$个到顺磁体的0个。在链的两端存在杂质（耦合发生改变）时，会出现边界态，这些边界态与顺磁相或完全铁磁相共存。对于长链，可采用连续近似来阐明相的结构；在连续描述中，温度低于其出现的临界温度时的磁化态对应扭结孤子。
英文摘要
We study magnets composed of molecules with an arbitrary number $m$ of magnetically active atoms in a chain configuration interacting with nearest-neighbor couplings. We derive the thermodynamics of a chain of spin-$j$ $SU(2)$ magnetic atoms using a mean-field approach and determine the equilibrium states and stability conditions. The system exhibits a rich phase structure with a cascade of ferromagnetic phase transitions, their number ranging from $m$, for maximal ferromagnets, to zero, for paramagnets, depending on the relative strengths of the couplings. In the presence of impurities (modified couplings) at the ends of the chain, boundary states emerge that coexist with the paramagnetic phase or the fully ferromagnetic phase. For long chains, a continuum approximation can be taken that clarifies the structure of the phases. In the continuum description, magnetized states at temperatures lower than the critical temperature at which they appear correspond to kink solitons.
Comments45 pages, 6 figures
