论文标题
哈伯德模型中的Skyrmion和涡流晶体
Skyrmion and vortex crystals in the Hubbard model
论文作者
论文摘要
巡回磁体中的电荷和自旋度之间的相互互动导致中心粒对称和非中心对称宿主的众多拓扑自旋纹理，例如磁性天空和涡流晶体。同时，它们的稳定化已在系统中进行了广泛的研究，包括经典的局部旋转。在这里，我们研究了中央三角形哈伯德模型中Skyrmion晶体的实现，其中电子的巡回性质起着更重要的作用。通过执行自洽的平均场计算，我们发现两种具有空间不均匀电荷调制的天空晶体在零磁场处出现在基态处。此外，我们获得了另一个非稳态晶体相，没有净标量性手性在Skyrmion晶相的附近。我们表明，后一种涡流晶体在施加的磁场中表现出拓扑相变为不同的天空相。我们的结果提供了在没有局部矩时的巡回磁铁中的天空和涡流晶体的可能性。
A mutual interplay between the charge and spin degrees of freedom in itinerant magnets leads to a plethora of topological spin textures, such as magnetic skyrmion and vortex crystals, in both centrosymmetric and noncentrosymmetric hosts. Meanwhile, their stabilization has been extensively studied in the system including the classical localized spins. We here study a realization of the skyrmion crystal in the centrosymmetric triangular-lattice Hubbard model, where the itinerant nature of electrons plays a more significant role. By performing the self-consistent mean-field calculations, we find that two types of skyrmion crystals with spatially nonuniform charge modulations appear in the ground state at a zero magnetic field. Moreover, we obtain another noncoplanar vortex crystal phase without a net scalar chirality in the vicinity of the skyrmion crystal phase. We show that the latter vortex crystal exhibits the topological phase transition to a different skyrmion phase in an applied magnetic field. Our results provide a possibility of the skyrmion and vortex crystals in itinerant magnets without the localized moments.
