Siu Zhuo Bin, Chang Jian-Yuan, Tan Seng Ghee, Jalil Mansoor B A, Chang Ching-Ray
Department of Electrical and Computer Engineering, National University of Singapore, Singapore, Singapore.
Graduate Institute of Applied Physics and Department of Physics, National Taiwan University, Taipei, 10617, Taiwan.
Sci Rep. 2018 Nov 7;8(1):16497. doi: 10.1038/s41598-018-34903-9.
In this work, we study the effect of introducing a periodic curvature on nanostructures, and demonstrate that the curvature can lead to a transition from a topologically trivial state to a non-trivial state. We first present the Hamiltonian for an arbitrarily curved nanostructure, and introduce a numerical scheme for calculating the bandstructure of a periodically curved nanostructure. Using this scheme, we calculate the bandstructure for a sinusoidally curved two-dimensional electron gas. We show that the curvature can lead to a partner switching reminiscent of a topological phase transition at the time reversal invariant momenta. We then study the Bernevig-Hughes-Zhang (BHZ) Hamiltonian for a two-dimensional quantum well. We show that introducing a curvature can lead to the emergence of topological surface states.
在这项工作中，我们研究了在纳米结构中引入周期性曲率的影响，并证明这种曲率可以导致从拓扑平凡态到非平凡态的转变。我们首先给出任意弯曲纳米结构的哈密顿量，并引入一种数值方案来计算周期性弯曲纳米结构的能带结构。使用该方案，我们计算了正弦弯曲二维电子气的能带结构。我们表明，这种曲率可以导致在时间反演不变动量处出现类似于拓扑相变的伙伴交换。然后，我们研究了二维量子阱的Bernevig-Hughes-Zhang（BHZ）哈密顿量。我们表明，引入曲率可以导致拓扑表面态的出现。
