论文标题
来自偶极硬球的铁磁冷冻结构以中等和小体积的分数
Ferromagnetic frozen structures from the dipolar hard spheres fluid at moderate and small volume fractions
论文作者
论文摘要
我们研究了具有或没有单轴各向异性的偶极硬球（DHS）集合的磁相图，并通过钢化蒙特卡洛模拟在无序结构上冻结。关键点是考虑一种各向异性结构，该结构是从偶极硬球的液态获得的，在低温下以极化状态冷冻。冻结的反温度$β_F$确定结构的各向异性程度，该结构通过结构性列表参数量化，$λ_s$。非零单轴各向异性的情况仅在其无限强的强度极限中被视为，其中系统在偶极ising模型中转换（DIM）。这项工作的重要发现是，以这种方式构建冷冻结构的DHS和昏暗的既呈现出低于阈值的体积分数的铁磁相，其中相应的各向同性DHS系统在低温下表现出旋转玻璃相。
We study the magnetic phase diagram of an ensemble of dipolar hard spheres (DHS) with or without uniaxial anisotropy and frozen in position on a disordered structure by tempered Monte Carlo simulations. The crucial point is to consider an anisotropic structure, obtained from the liquid state of the dipolar hard spheres fluid, frozen in its polarized state at low temperature. The freezing inverse temperature $β_f$ determines the degree of anisotropy of the structure which is quantified through a structural nematic order parameter, $λ_s$. The case of the non zero uniaxial anisotropy is considered only in its infinitely strong strength limit where the system transforms in a dipolar Ising model (DIM). The important finding of this work is that both the DHS and the DIM with a frozen structure build in this way present a ferromagnetic phase at volume fractions below the threshold value where the corresponding isotropic DHS systems exhibit a spin glass phase at low temperature.
