Center for Statistical and Theoretical Condensed Matter Physics, and Department of Physics, Zhejiang Normal University, Jinhua 321004, People's Republic of China.
J Phys Condens Matter. 2013 Jul 31;25(30):305602. doi: 10.1088/0953-8984/25/30/305602. Epub 2013 Jul 3.
We study the topological quantum phase transitions of tight-binding electrons on two representative multi-band lattice models with superimposed staggered fluxes: the kagomé lattice and the square-octagon lattice. By considering the nearest-neighbor and next-nearest-neighbor hopping parameters (t1 and t2) and the staggered flux parameter φ, we obtain rich topological quantum phase transitions for both the lattices. The whole phase diagram for the kagomé lattice in the t2-φ parameter space is obtained. We also illustrate a series of topological quantum phase transitions as well as topological bands of high Chern numbers for the square-octagon lattice. Furthermore, interesting topological flat bands with high flatness ratios (e.g. of about 43) are found in the square-octagon lattice, especially when the next-next-nearest-neighbor hopping (t3) is included.
我们研究了紧束缚电子在两个具有叠加交错通量的代表性多带晶格模型（三角晶格和方八角晶格）上的拓扑量子相变。通过考虑最近邻和次近邻跳跃参数（t1 和 t2）和交错通量参数 φ，我们得到了这两个晶格的丰富的拓扑量子相变。我们得到了三角晶格在 t2-φ 参数空间中的整个相图。我们还说明了一系列的拓扑量子相变以及方八角晶格的高陈数拓扑能带。此外，在方八角晶格中发现了有趣的拓扑平坦带，其平坦度比（例如约为 43）很高，特别是当包括次近邻跳跃（t3）时。
