标题： 无晶体对称性的反磁性 显示英文标题

标题： Altermagnetism Without Crystal Symmetry

摘要： 反铁磁性是一种共线性磁有序态，在这种状态下，自旋相反的粒子在实空间旋转下发生交换。因此，寻找物理实现主要集中于具有特定旋转对称性的晶体固体。在这里，我们展示了反铁磁性也可以出现在非晶态系统中，例如非晶态固体，尽管缺乏全局旋转对称性。我们在非晶格子上构建了一个哈密顿量，每个位点有两个方向轨道，并且相互作用在自旋旋转下保持不变。反铁磁性随后由于每个原子周围的自旋和轨道自由度自发对称破缺而出现，表现出共同的点群对称性。这种形式的反铁磁性表现出各向异性的自旋输运和自旋谱函数，这些都是可以通过实验测量的。我们的机制可以推广到任意晶格和任意反铁磁序，从而将反铁磁现象的研究扩展到非晶态系统。 显示英文摘要

摘要： Altermagnetism is a collinear magnetic order in which opposite spin species are exchanged under a real-space rotation. Hence, the search for physical realizations has focussed on crystalline solids with specific rotational symmetry. Here, we show that altermagnetism can also emerge in non-crystalline systems, such as amorphous solids, despite the lack of global rotational symmetries. We construct a Hamiltonian with two directional orbitals per site on an amorphous lattice with interactions that are invariant under spin rotation. Altermagnetism then arises due to spontaneous symmetry breaking in the spin and orbital degrees of freedom around each atom, displaying a common point group symmetry. This form of altermagnetism exhibits anisotropic spin transport and spin spectral functions, both experimentally measurable. Our mechanism generalizes to any lattice and any altermagnetic order, opening the search for altermagnetic phenomena to non-crystalline systems.