论文标题
三重 - $ \ MATHCAL {Q} $由四极互动引起的部分磁性订单：uni $ _4 $ b的Triforce订单方案
Triple-$\mathcal{Q}$ partial magnetic orders induced by quadrupolar interactions: Triforce order scenario for UNi$_4$B
论文作者
论文摘要
从理论上讲，我们在$ {\ rm uni_4b} $中调查了可能的对称性状态，构建了局部化的三重态晶体晶体电场模型。长期以来，其低温对称性阶段以$ {\ rm uni_4b} $在$ {\ rm uni_4b} $中被认为是磁性的磁环序，形成了原子尺度涡流晶格，在每个涡流的每个中心都有无序的位点。但是，由于其各向异性存在矛盾，最近对电流诱导的磁化的观察结果提供了有关该阶参数有效性的重新研究。我们的模型考虑了四极自由度的自由度，最近的声音软化证明了其重要性。我们发现四极力矩在确定有序状态的磁性结构方面起着重要作用。对于广泛的参数空间，我们在36个地点的平均场分析中获得了两个三重-MATHCAL {Q} $磁性订单：环形序列，另一个具有与圆环顺序相同的无序位点。我们在其磁性结构之后将后者命名为``Triforce''订单。重要的是，Triforce顺序具有与环形序列完全相同的旋转结构因子，而三重 - $ \ MATHCAL {Q} $结构的相位因子的相位因子不同。我们表明，当考虑到$ {\ rm uni_4b} $的逼真的晶体结构时，Triforce顺序与观察到的电流诱导的磁化一致。我们将Triforce Order的预测与目前可用的实验数据进行了比较，并讨论了三重机制的可能应用 - $ \ Mathcal {Q} $ orders oders oders oders oders {q} $ orders or anistropic相关系统。
We theoretically investigate possible symmetry-broken states in ${\rm UNi_4B}$, constructing a localized pseudo triplet crystalline-electric field model. For a long time, its low-temperature symmetry-broken phase in ${\rm UNi_4B}$ has been considered to be a magnetic toroidal order forming atomic-scale vortices lattice with disordered sites at each center of the vortices. However, recent observation of current-induced magnetizations offers a reinvestigation about the validity of this order parameter because of the contradiction in their anisotropy. Our model takes into account the quadrupole degrees of freedom, whose importance is recently evidenced by the sound-velocity softening. We find that the quadrupole moments play an important role in determining the magnetic structure in the ordered states. For a wide range of parameter space, we obtain two triple-$\mathcal{Q}$ magnetic orders in our 36-site mean-field analysis: toroidal order and another one with the same number of disordered sites as in the toroidal order. We name the latter ``triforce'' order after its magnetic structure. Importantly, the triforce order possesses exactly the same spin structure factor as the toroidal order does, while the phase factors in the superposition of the triple-$\mathcal{Q}$ structure are different. We show that the triforce order is consistent with the observed current-induced magnetization when the realistic crystal structure of ${\rm UNi_4B}$ is taken into account. We compare the predictions of the triforce order with the experimental data available at present in detail and also discuss possible applications of the present mechanism of triple-$\mathcal{Q}$ orders to anisotropic correlated systems.
