摘要翻译:
将实空间模型映射到时间尺度上,提出了一维和二维的Su-Schrieffer-Heeger哈密顿量的路径积分描述。晶格自由度是时间的经典函数,并精确地积分出来,而电子粒子的路径则用量子力学的方法处理。该方法考虑了电子跳变过程的变化范围。系统的自由能及其温度导数是通过对主要贡献于总配分函数的相关粒子路径系综的任意$T$求和来计算的。在低$T$区,{\It热容比T}没有出现玻璃状行为所特有的上升。这一特征在正方形晶格中比在线性链中更大,因为在高维度中,总的跳跃势对总作用的贡献更大。用路径积分累积量展开方法研究了电子-声子非谐相互作用对声子子系统的影响。
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英文标题:
《Path Integral Methods in the Su-Schrieffer-Heeger Polaron Problem》
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作者:
Marco Zoli
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最新提交年份:
2007
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分类信息:
一级分类:Physics 物理学
二级分类:Materials Science 材料科学
分类描述:Techniques, synthesis, characterization, structure. Structural phase transitions, mechanical properties, phonons. Defects, adsorbates, interfaces
技术,合成,表征,结构。结构相变,力学性质,声子。缺陷,吸附质,界面
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一级分类:Physics 物理学
二级分类:Statistical Mechanics 统计力学
分类描述:Phase transitions, thermodynamics, field theory, non-equilibrium phenomena, renormalization group and scaling, integrable models, turbulence
相变,热力学,场论,非平衡现象,重整化群和标度,可积模型,湍流
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一级分类:Statistics 统计学
二级分类:Applications 应用程序
分类描述:Biology, Education, Epidemiology, Engineering, Environmental Sciences, Medical, Physical Sciences, Quality Control, Social Sciences
生物学,教育学,流行病学,工程学,环境科学,医学,物理科学,质量控制,社会科学
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英文摘要:
I propose a path integral description of the Su-Schrieffer-Heeger Hamiltonian, both in one and two dimensions, after mapping the real space model onto the time scale. While the lattice degrees of freedom are classical functions of time and are integrated out exactly, the electron particle paths are treated quantum mechanically. The method accounts for the variable range of the electronic hopping processes. The free energy of the system and its temperature derivatives are computed by summing at any $T$ over the ensemble of relevant particle paths which mainly contribute to the total partition function. In the low $T$ regime, the {\it heat capacity over T} ratio shows un upturn peculiar to a glass-like behavior. This feature is more sizeable in the square lattice than in the linear chain as the overall hopping potential contribution to the total action is larger in higher dimensionality. The effects of the electron-phonon anharmonic interactions on the phonon subsystem are studied by the path integral cumulant expansion method.
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PDF链接:
https://arxiv.org/pdf/705.1428