标题： 通过局部宇称混合的自发多极序 显示英文标题

标题： Spontaneous multipole ordering by local parity mixing

摘要： 自旋轨道耦合系统中空间反演对称性的破坏导致了不同宇称轨道之间的混合，这导致了不寻常的电子结构和输运特性。我们理论研究了由宇称混合引起的多极序的可能性。特别是，我们关注宇称混合以子晶格依赖形式出现的系统。从具有这种局域宇称混合的周期性安德森模型出发，我们推导出一个扩展的Kondo晶格模型，其中巡游电子与局域自旋之间存在子晶格依赖的反对称交换耦合。通过变分计算、模拟退火和蒙特卡洛模拟，我们表明在准一维之字形晶格上的模型在半填充及附近表现出由磁矢量和四极矩成分组成的奇宇称多极序。多极序导致了能带变形，包括能带底的移动和电磁响应。结果表明，在具有局域宇称混合的多轨道系统中，不寻常的奇宇称多极序将被广泛观察到。 显示英文摘要

摘要： Broken spatial inversion symmetry in spin-orbital coupled systems leads to a mixing between orbitals with different parity, which results in unusual electronic structures and transport properties. We theoretically investigate the possibility of multipole ordering induced by a parity mixing. In particular, we focus on the system in which the parity mixing appears in a sublattice-dependent form. Starting from the periodic Anderson model with such a local parity mixing, we derive an extended Kondo lattice model with sublattice-dependent antisymmetric exchange couplings between itinerant electrons and localized spins. By the variational calculation, simulated annealing, and Monte Carlo simulation, we show that the model on a quasi-one-dimensional zig-zag lattice exhibits an odd-parity multipole order composed of magnetic toroidal and quadrupole components at and near half filling. The multipole order causes a band deformation with the band bottom shift and a magnetoelectric response. The results suggest that unusual odd-parity multipole orders will be widely observed in multi-orbital systems with local parity mixing.