Majorana edge magnetization in the Kitaev honeycomb model
Majorana edge magnetization in the Kitaev honeycomb model
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DOI：
10.1103/physrevb.99.184418
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发表时间：
2018-11
影响因子：
3.7
通讯作者：
T. Mizoguchi;T. Koma
中科院分区：
文献类型：
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作者：
T. Mizoguchi;T. Koma
我们提出了一种方法来检测Kitaev磁铁的边缘马约拉纳费米子的特殊性。众所周知，当单个复费米子分裂成分别位于样品磁体的左边缘和右边缘的真实的实部和虚部时，实现了一对马约拉纳边缘模式。考虑到马约拉纳费米子的这一特性以及马约拉纳边缘零模的存在所导致的基态简并性，样品磁体边缘处的自旋被认为是一种特殊的“lq\lq自由”自旋，当施加足够弱的外磁场时，这种自旋表现出单向磁化，而没有任何横向磁化。对于Kitaev蜂窝模型，我们通过对自由费米子哈密顿量进行对角化，得到了Majorana边缘磁化强度的表达式。由此获得的磁化曲线确实显示了预期的行为。从弱拓扑的角度阐明了Majorana边平带与体缠绕数之间的关系。
We propose an approach to detect the peculiarity of Majorana fermions at the edges of Kitaev magnets. As is well known, a pair of Majorana edge modes is realized when a single complex fermion splits into real and imaginary parts which are, respectively, localized at the left and right edges of a sample magnet. Reflecting both of this peculiarity of the Majorana fermions and the ground-state degeneracy caused by the existence of the Majorana edge zero modes, the spins at the edges of the sample magnet are expected to behave as a peculiar \lq\lq free" spin which exhibits a unidirectional magnetization without any transverse magnetization when applied a sufficiently weak external magnetic field. For the Kitaev honeycomb model, we obtain the expression of the Majorana edge magnetization by relying on standard techniques to diagonalize a free fermion Hamiltonian. The magnetization profile thus obtained indeed shows the expected behavior. We also elucidate the relation between the Majorana edge flat band and the bulk winding number from a weak topological point of view.