中国物理B ›› 2011, Vol. 20 ›› Issue (7): 76701-076701.doi: 10.1088/1674-1056/20/7/076701

• CONDENSED MATTER: STRUCTURAL, MECHANICAL, AND THERMAL PROPERTIES • 上一篇    下一篇

Quantum diffusion in bilateral doped chains

金福报, 张凯旺, 钟建新   

  1. Department of Physics, Xiangtan University, Xiangtan 411105, China
  • 收稿日期:2010-12-12 修回日期:2011-01-23 出版日期:2011-07-15 发布日期:2011-07-15

Quantum diffusion in bilateral doped chains

Jin Fu-Bao(金福报), Zhang Kai-Wang(张凯旺), and Zhong Jian-Xin(钟建新)   

  1. Department of Physics, Xiangtan University, Xiangtan 411105, China
  • Received:2010-12-12 Revised:2011-01-23 Online:2011-07-15 Published:2011-07-15

摘要: In this paper, we quantitatively study the quantum diffusion in a bilateral doped chain, which is randomly doped on both sides. A tight binding approximation and quantum dynamics are used to calculate the three electronic characteristics: autocorrelation function C(t), the mean square displacement d(t) and the participation number P(E) in different doping situations. The results show that the quantum diffusion is more sensitive to the small ratio of doping than to the big one, there exists a critical doping ratio q0, and C(t), d(t) and P(E) have different variation trends on different sides of q0. For the self-doped chain, the doped atoms have tremendous influence on the central states of P(E), which causes the electronic states distributed in other energy bands to aggregate to the central band (E=0) and form quasi-mobility edges there. All of the doped systems experience an incomplete transition of metal-semiconductor-metal.

Abstract: In this paper, we quantitatively study the quantum diffusion in a bilateral doped chain, which is randomly doped on both sides. A tight binding approximation and quantum dynamics are used to calculate the three electronic characteristics: autocorrelation function C(t), the mean square displacement d(t) and the participation number P(E) in different doping situations. The results show that the quantum diffusion is more sensitive to the small ratio of doping than to the big one, there exists a critical doping ratio q0, and C(t), d(t) and P(E) have different variation trends on different sides of q0. For the self-doped chain, the doped atoms have tremendous influence on the central states of P(E), which causes the electronic states distributed in other energy bands to aggregate to the central band (E=0) and form quasi-mobility edges there. All of the doped systems experience an incomplete transition of metal-semiconductor-metal.

Key words: quantum diffusion, doped chain, metal semiconductor transition

中图分类号:  (Defects, impurities, and diffusion)

  • 67.80.dj
71.55.Jv (Disordered structures; amorphous and glassy solids) 71.30.+h (Metal-insulator transitions and other electronic transitions)