Magnetic order on a topological insulator surface with warping and proximity-induced superconductivity
Magnetic order on a topological insulator surface with warping and proximity-induced superconductivity
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DOI：
10.1103/physrevb.91.155405
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发表时间：
2015-04-06
影响因子：
3.7
通讯作者：
Schoen, Gerd
中科院分区：
文献类型：
--
作者：
Mendler, Daniel;Kotetes, Panagiotis;Schoen, Gerd
我们确定的拓扑绝缘体（TI）的表面上的磁序的性质，由于六边形翘曲和由此产生的费米面（FS）嵌套在存在的排斥哈伯德相互作用的发展。为此，我们研究了自旋磁化率，并推导出一个朗道理论来比较不同的可及相位。对于接近六边形FS和足够强的相互作用，磁基态由skyrmion晶格形成，即，通过三个螺旋自旋密度波的叠加，保持C-3对称性。磁基态是拓扑非平凡的，具有非零的Skyrmion电荷，可以通过施加磁场来稳定和控制。通过使TI接近常规超导体，可以设计C-3对称拓扑超导体。我们探讨了相图的修改以及Skyrmion结构和多极分布的超电流之间的相互影响，这可以提供有关潜在的Skyrmion电荷的信息。
We determine the nature of the magnetic order on the surface of a topological insulator (TI) which develops due to hexagonal warping and the resulting Fermi surface (FS) nesting in the presence of a repulsive Hubbard interaction. For this purpose we investigate the spin susceptibility and derive a Landau theory to compare the different accessible phases. For a nearly hexagonal FS and sufficiently strong interaction the magnetic ground state is formed by a skyrmion lattice, i.e., by a superposition of three helical spin density waves which preserves C-3 symmetry. The magnetic ground state is topologically nontrivial with a nonzero skyrmion charge, which can be stabilized and controlled by an applied magnetic field. By bringing the TI in proximity to a conventional superconductor one can engineer a C-3-symmetric topological superconductor. We explore the modification of the phase diagram as well as the mutual influence between the skyrmion structure and a multipolar distribution of supercurrents, which can provide information about the underlying skyrmion charge.