arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 1010.3207cond-mat.str-el
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一维Su-Schrieffer-Heeger模型中单极子的锐跃迁

Sharp transition for single polarons in the one-dimensional Su-Schrieffer-Heeger model

D. J. J. Marchand, G. De Filippis, V. Cataudella, M. Berciu, N. Nagaosa, N. V. Prokof'ev, A. S. Mishchenko, P. C. E. Stamp

摘要:

我们使用四种不同的方法(三种数值方法和一种解析方法)研究了Su-Schrieffer-Heeger(SSH)模型中的单极子。极化子显示出从弱耦合到强耦合的平滑交叉,作为电子-声子耦合强度$λ$的函数,在所有的模型中,这种耦合仅取决于声子动量$q$。在SSH模型的耦合也取决于电子动量$k$,我们发现它有一个尖锐的过渡,在临界耦合强度$λ_c$,之间的状态与零和非零的基态的动量。极化子的所有其他性质在$λ= λ_c$也是奇异的,除了极化子云中声子的平均数。这个结果代表了所有依赖于$k$和$q$耦合的极化子,并且将具有重要的实验结果(例如,在ARPES和电导率实验中)。

英文摘要:

We study a single polaron in the Su-Schrieffer-Heeger (SSH) model using four different techniques (three numerical and one analytical). Polarons show a smooth crossover from weak to strong coupling, as a function of the electron-phonon coupling strength $λ$, in all models where this coupling depends only on phonon momentum $q$. In the SSH model the coupling also depends on the electron momentum $k$; we find it has a sharp transition, at a critical coupling strength $λ_c$, between states with zero and nonzero momentum of the ground state. All other properties of the polaron are also singular at $λ= λ_c$, except the average number of phonons in the polaronic cloud. This result is representative of all polarons with coupling depending on $k$ and $q$, and will have important experimental consequences (eg., in ARPES and conductivity experiments).

机构、总结、中文摘要均由AI分析而来,可能存在错误,请以论文正文为准。

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