Ground state and polaron and bipolaron excited states in polydiacetylene  

作　　者：LI Yuan1, HU Guichao1, XIA Caijuan1, LIU Desheng1,2 & XIE Shijie1,2 1. School of Physics and Microelectronics, Shandong University, Jinan 250100, China 2. National Key Laboratory of Crystal Materials, Shandong University, Jinan 250100, China 

出　　处：《Science China(Physics,Mechanics & Astronomy)》2006年第4期430-439,共10页中国科学：物理学、力学、天文学（英文版）

基　　金：This work was supported by the National Natural Science Foundation of China (Grant Nos. 10574082, 10474056, 90403110 and 50323006) ; the Natural Science Foundation of Shandong Province (Grant No. Z2005A01).

摘　　要：The electronic properties of ground state and charged excited states of nondegenerate polydiacetylene were investigated by means of a tight-binding model. The parameters of the model were obtained by comparison of the experimental and other theoretical results. It was found that there is a stable dimerized structure of polydiacetylene in ground state and the doping induces the nonlinear excitations, such as polarons and bipolarons. In order to compare the stability of polaron and bipolaron, the creation energy and binding energy were separately defined. By neglecting the electron-electron Coulomb interaction, a bipolaron is more stable than two independent polarons.The electronic properties of ground state and charged excited states of nondegenerate polydiacetylene were investigated by means of a tight-binding model. The parameters of the model were obtained by comparison of the experimental and other theoretical results. It was found that there is a stable dimerized structure of polydiacetylene in ground state and the doping induces the nonlinear excitations, such as polarons and bipolarons. In order to compare the stability of polaron and bipolaron, the creation energy and binding energy were separately defined. By neglecting the electron-electron Coulomb interaction, a bipolaron is more stable than two independent polarons.

关 键 词：dimerization  polaron  bipolaron  BINDING energy. 

分 类 号：O471[理学—半导体物理]