Topological phase in one-dimensional Rashba wire

• 作者: 刘军丰 汪军 汪萨克
• 来源期刊: 中国物理B（英文版）
• 关键词: one-dimensional topological phase Rashba spin-orbit interaction spatial modulation quantized pump
• 年，卷（期）: 2016,（7）
• 页码范围: 077305-1-077305-8
• 页数: 1页
• 语种: 英文
• DOI: 10.1088/1674-1056/25/7/077305

摘要

We study the possible topological phase in a one-dimensional (1D) quantum wire with an oscillating Rashba spin–orbital coupling in real space. It is shown that there are a pair of particle–hole symmetric gaps forming in the bulk energy band and fractional boundary states residing in the gap when the system has an inversion symmetry. These states are topo-logically nontrivial and can be characterized by a quantized Berry phase ±πor nonzero Chern number through dimensional extension. When the Rashba spin–orbital coupling varies slowly with time, the system can pump out 2 charges in a pump-ing cycle because of the spin flip effect. This quantized pumping is protected by topology and is robust against moderate disorders as long as the disorder strength does not exceed the opened energy gap.