We investigate the evolution of multicritical points under pressure and magnetic field in a model described by two 5f bands (called α and β) that hybridize with a single itinerant conduction band. The interaction is given by the direct Coulomb and the Hund’s rule exchange terms. Three types of orderings are considered: two conventional spin density waves (SDWs) and an exotic SDW, i.e., with no magnetic moment formation. The conventional SDWs phases, are characterized by and , respectively, where and are the intraband staggered magnetizations. The exotic SDW, which has time reversal symmetry, is described by a purely imaginary order parameter. This phase is related to a band mixing given by the spin-flip part of the Hund’s rule exchange interaction. As result, without magnetic field, the phase diagrams of temperature (T) versus pressure (given by the variation of the bandwidth (W)) shows a sequence of phase transitions involving the three phases which gives rise to multicritical points. The presence of the magnetic field (h _z ) has drastic effects on part of the phase diagram and the location of the multicritical points.

我们在由两个 5 f带（称为α和β）描述的模型中研究了压力和磁场下多临界点的演变，这些带与单个巡回导带混合。相互作用由直接库仑和洪德规则交换项给出。考虑了三种类型的排序：两种传统的自旋密度波 (SDW) 和一种奇异的 SDW，即没有磁矩形成。传统的 SDWs 阶段分别由和表征，其中和是带内交错磁化。具有时间反转对称性的奇异 SDW 由纯虚序参数描述。这个阶段与 Hund 规则交换相互作用的自旋翻转部分给出的带混合有关。结果，在没有磁场的情况下，温度 ( T ) 与压力 (由带宽 ( W )的变化给出)的相图显示了涉及三个相的一系列相变，从而产生了多临界点。磁场 ( h _z ) 的存在对相图的一部分和多临界点的位置具有显着影响。