论文标题
从保利Promagnetism转变为钒中的Curie-Weiss行为
Transition from Pauli paramagnetism to Curie-Weiss behaviour in vanadium
论文作者
论文摘要
我们通过密度功能和动态平均场理论的结合研究电子相关性及其对BCC气染磁性的影响。计算出的均匀磁化率{在BCC结构中}在低温下是Pauli类型的，而在较高温度下，它遵守Curie-Weiss定律。因此，我们在不引入马氏体相变的情况下定性地重现了磁敏感性的实验温度依赖性。我们针对局部自旋旋转相关功能和局部敏感性的结果表明，由于部分形成局部磁矩，库里 - 韦斯的行为出现，该磁矩的部分形成起源于$ t_ {2g} $状态，并且由于hund的规则耦合而引起的局部自旋相关性。同时，费米子准颗粒仍然明确定义，而局部矩的形成则伴随着偏离费米 - 液体行为的偏差。尤其是，$ t_ {2g} $状态的自我能力显示了非分析频率依赖性，这是自旋冻结行为的特征，而Quasiparticle阻尼在中等温度范围内的温度差异近似线性变化$ 200 $ - $ 700 $ 〜K。通过分析静态磁敏感性的动量依赖性，我们发现了不稳定的磁相关性，这可能为低温下的非常规超导性提供了一种机制。
We study electron correlations and their impact on magnetic properties of bcc vanadium by a combination of density functional and dynamical mean-field theory. The calculated uniform magnetic susceptibility {in bcc structure} is of Pauli type at low temperatures, while it obeys the Curie-Weiss law at higher temperatures. Thus, we qualitatively reproduce the experimental temperature dependence of magnetic susceptibility without introducing the martensitic phase transition. Our results for local spin-spin correlation function and local susceptibility reveal that the Curie-Weiss behavior appears due to partial formation of local magnetic moments, which originate from $t_{2g}$ states and occur due to local spin correlations caused by Hund's rule coupling. At the same time, the fermionic quasiparticles remain well-defined, while the formation of local moments is accompanied by a deviation from the Fermi-liquid behavior. In particular, the self-energy of the $t_{2g}$ states shows the non-analytic frequency dependence, which is a characteristic of the spin-freezing behavior, while the quasiparticle damping changes approximately linearly with temperature in the intermediate temperature range $200$--$700$~K. By analyzing the momentum dependence of static magnetic susceptibility, we find incommensurate magnetic correlations, which may provide a mechanism for unconventional superconductivity at low temperatures.
