标题： 石墨烯纳米带异质结中的磁调制拓扑相 显示英文标题

标题： Magnetically tuned topological phase in graphene nanoribbon heterojunctions

摘要： 拓扑学与磁性的相互作用常常会引发奇特的量子相。 在这里，我们报告了一种可实现的方案，通过本征磁性来设计稳健的$\mathbb{Z}_{2}$拓扑结构，这种磁性来源于连接两个不同宽度的扶手椅段的锯齿形段，在一维石墨烯纳米带异质结中。 我们的第一性原理和模型模拟表明，出现的自旋极化显著改变了结态之间的二聚化，形成了依赖于磁配置的特殊SSH机制。 有趣的是，磁态中的拓扑相仅由窄扶手椅段的宽度决定，这与正常态的情况形成鲜明对比。 此外，出现的磁性使体能带隙比非磁态大一个数量级。 我们还讨论了$\mathbb{Z}$的结态拓扑性质以及拓扑末端态的终止依赖性。 我们的研究为调节石墨烯纳米带异质结构中的拓扑性质提供了新途径，为未来的一维拓扑器件和分子尺度自旋电子学提供了新平台。 显示英文摘要

摘要： The interplay between topology and magnetism often triggers the exotic quantum phases. Here, we report an accessible scheme to engineer the robust $\mathbb{Z}_{2}$ topology by intrinsic magnetism, originating from the zigzag segment connecting two armchair segments with different width, in one-dimensional graphene nanoribbon heterojunctions. Our first-principle and model simulations reveal that the emergent spin polarization substantially modifies the dimerization between junction states, forming the special SSH mechanism depending on the magnetic configurations. Interestingly, the topological phase in magnetic state is only determined by the width of the narrow armchair segment, in sharp contrast with that in the normal state. In addition, the emergent magnetism increases the bulk energy band gap by an order of magnitude than that in the nonmagnetic state. We also discuss the $\mathbb{Z}$ topology of the junction states and the termination-dependent of topological end states. Our results bring new way to tune the topology in graphene nanoribbon heterostructure, providing a new platform for future one-dimensional topological devices and molecular-scale spintronics.