中国物理B ›› 2016, Vol. 25 ›› Issue (7): 77303-077303.doi: 10.1088/1674-1056/25/7/077303

• CONDENSED MATTER: ELECTRONIC STRUCTURE, ELECTRICAL, MAGNETIC, AND OPTICAL PROPERTIES • 上一篇    下一篇

Effect of disorders on topological phases inone-dimensional optical superlattices

Zhizhou Wang(王志宙), Yidong Wu(吴一东), Huijing Du(杜会静), Xili Jing(井西利)   

  1. School of Science, Yanshan University, Qinhuangdao 066004, China
  • 收稿日期:2016-02-17 修回日期:2016-03-16 出版日期:2016-07-05 发布日期:2016-07-05
  • 通讯作者: Yidong Wu, Huijing Du E-mail:wuyidong@ysu.edu.cn;hjdu@ysu.edu.cn
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No. 41174116), the Graduate Student Education Teaching Reform Project, China (Grant No. JG201512), and the Young Teachers' Research Project of Yanshan University, China (Grant No. 13LGB028).

Effect of disorders on topological phases inone-dimensional optical superlattices

Zhizhou Wang(王志宙), Yidong Wu(吴一东), Huijing Du(杜会静), Xili Jing(井西利)   

  1. School of Science, Yanshan University, Qinhuangdao 066004, China
  • Received:2016-02-17 Revised:2016-03-16 Online:2016-07-05 Published:2016-07-05
  • Contact: Yidong Wu, Huijing Du E-mail:wuyidong@ysu.edu.cn;hjdu@ysu.edu.cn
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No. 41174116), the Graduate Student Education Teaching Reform Project, China (Grant No. JG201512), and the Young Teachers' Research Project of Yanshan University, China (Grant No. 13LGB028).

摘要: In a recent paper, Lang et al. proposed that edge states and topological phases can be observed in one-dimensional optical superlattices. They showed that the topological phases can be revealed by observing the density profile of a trapped fermion system, which displays plateaus with their positions. However, disorders are not considered in their model. To study the effect of disorders on the topological phases, we introduce random potentials to the model for optical superlattcies. Our calculations show that edge states are robust against the disorders. We find the edge states are very sensitive to the number of the sites in the optical superlattice and we propose a simple rule to describe the relationship between the edge states and the number of sites. The density plateaus are also robust against weak disorders provided that the average density is calculated over a long interval. The widths of the plateaus are proportional to the widths of the bulk energy gaps when there are disorders. The disorders can diminish the bulk energy gaps. So the widths of the plateaus decrease with the increase of disorders and the density plateaus disappear when disorders are too strong. The results in our paper can be used to guide the experimental detection of topological phases in one-dimensional systems.

关键词: edge state, topological phase, optical superlattices

Abstract: In a recent paper, Lang et al. proposed that edge states and topological phases can be observed in one-dimensional optical superlattices. They showed that the topological phases can be revealed by observing the density profile of a trapped fermion system, which displays plateaus with their positions. However, disorders are not considered in their model. To study the effect of disorders on the topological phases, we introduce random potentials to the model for optical superlattcies. Our calculations show that edge states are robust against the disorders. We find the edge states are very sensitive to the number of the sites in the optical superlattice and we propose a simple rule to describe the relationship between the edge states and the number of sites. The density plateaus are also robust against weak disorders provided that the average density is calculated over a long interval. The widths of the plateaus are proportional to the widths of the bulk energy gaps when there are disorders. The disorders can diminish the bulk energy gaps. So the widths of the plateaus decrease with the increase of disorders and the density plateaus disappear when disorders are too strong. The results in our paper can be used to guide the experimental detection of topological phases in one-dimensional systems.

Key words: edge state, topological phase, optical superlattices

中图分类号:  (Superlattices)

  • 73.21.Cd
05.30.Fk (Fermion systems and electron gas) 03.75.Hh (Static properties of condensates; thermodynamical, statistical, and structural properties)