中国物理B ›› 2009, Vol. 18 ›› Issue (11): 5038-5043.doi: 10.1088/1674-1056/18/11/071

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Coherent incoherent transition in the spin boson model with a super-ohmic bath

陈芝得1, 谢友兰2   

  1. (1)Department of Electronic Engineering, Jinan University, Guangzhou 510632, China; (2)Department of Physics, Jinan University, Guangzhou 510632, China
  • 收稿日期:2009-05-05 修回日期:2009-05-12 出版日期:2009-11-20 发布日期:2009-11-20
  • 基金资助:
    Project supported by the National Natural Science Foundation of China (Grant No 10575045).

Coherent--incoherent transition in the spin--boson model with a super-ohmic bath

Xie You-Lan(谢友兰)a) and Chen Zhi-De(陈芝得)b)†   

  1. a Department of Physics, Jinan University, Guangzhou 510632, China; b Department of Electronic Engineering, Jinan University, Guangzhou 510632, China
  • Received:2009-05-05 Revised:2009-05-12 Online:2009-11-20 Published:2009-11-20
  • Supported by:
    Project supported by the National Natural Science Foundation of China (Grant No 10575045).

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摘要： The temperature effect on tunnelling splitting in the spin--boson model with a super-ohmic bath is studied by the small polaron theory. The coherent--incoherent transition temperature is calculated and its dependence on dissipation strength and bare tunnelling splitting is analysed. In additional to the traditional transition point described in textbooks, a new kind of transition is found in the low dissipation region, showing different temperature dependence in the transition. The relation to the corresponding transition in the polaron--phonon system is also discussed.

Abstract: The temperature effect on tunnelling splitting in the spin--boson model with a super-ohmic bath is studied by the small polaron theory. The coherent--incoherent transition temperature is calculated and its dependence on dissipation strength and bare tunnelling splitting is analysed. In additional to the traditional transition point described in textbooks, a new kind of transition is found in the low dissipation region, showing different temperature dependence in the transition. The relation to the corresponding transition in the polaron--phonon system is also discussed.

Key words: the spin--boson model, coherent--incoherent transition, polaron--phonon system

中图分类号:  (Tunneling)

  • 73.43.Jn
73.21.-b (Electron states and collective excitations in multilayers, quantum wells, mesoscopic, and nanoscale systems) 63.22.-m (Phonons or vibrational states in low-dimensional structures and nanoscale materials)