Dirac fermion model associated with a second-order topological insulator
Dirac fermion model associated with a second-order topological insulator
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DOI：
10.1103/physrevb.99.165129
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发表时间：
2018-06
影响因子：
3.7
通讯作者：
T. Fukui
中科院分区：
文献类型：
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作者：
T. Fukui
我们研究了狄拉克费米子与希格斯场耦合的拓扑方面，希格斯场与Benalcazar等人引入的晶格模型相关。[Science 357，61（2017）]具有拓扑四极相位。利用指数定理，我们证明了哈密顿量的指数恰好由Higgs场的缠绕数给出，这意味着格点模型的角态属于一类定域在涡旋上的Jackiw-Rossi态.我们还计算了狄拉克费米子的电流密度与依赖于时间的破缺项，这是由Benalcazar等人提出的偶极泵。我们认为，总泵浦电荷是由一个整数有关的指数。
We study topological aspects of a Dirac fermion coupled with a Higgs field associated with the lattice model introduced by Benalcazar et al. [Science 357, 61 (2017)] which has the topological quadrupole phase. Using the index theorem, we show that the index of the Hamiltonian is just given by the winding number of the Higgs field, implying that a corner state of the lattice model belongs to the same class of the Jackiw-Rossi states localized at a vortex. We also calculate the current density of the Dirac fermion with a symmetry-breaking term dependent on time, which is associated with the dipole pump proposed by Benalcazar et al.. We argue that the total pumped charge is given by an integer related with the index.