arXivDaily arXiv每日学术速递 周一至周五更新
arXiv 2007.07364cond-mat.str-el
收藏

Peierls与Holstein模型在钙钛矿中的电子-声子耦合

Peierls versus Holstein models for describing electron-phonon coupling in perovskites

Yau-Chuen Yam, Mirko M. Moeller, George A. Sawatzky, Mona Berciu

摘要:

我们使用的动量平均近似与微扰的方法,在适当的限制,研究单一的极化子物理的钙钛矿晶格的灵感来自BaBiO 3。我们调查的Peierls型的电子-声子耦合,离子的运动调制站点之间的跳跃积分的值,并表明,它不能映射到更简单的一个频带Holstein模型在整个参数空间。这是因为Peierls极化子的色散具有急剧的转变,其中基态动量在布里渊区的高对称点之间跳跃,而Holstein极化子总是具有相同的基态动量。这些结果意味着,需要仔细考虑,以选择合适的模型,在这种复杂的晶格载流子-晶格耦合。

英文摘要:

We use the Momentum Average approximation together with perturbative approaches, in the appropriate limits, to study the single polaron physics on a perovskite lattice inspired by BaBiO3. We investigate electron-phonon coupling of the Peierls type whereby the motion of ions modulates the values of the hopping integrals between sites, and show that it cannot be mapped onto the simpler one-band Holstein model in the whole parameter space. This is because the dispersion of the Peierls polaron has sharp transitions where the ground-state momentum jumps between high-symmetry points in the Brillouin zone, whereas the Holstein polaron always has the same ground-state momentum. These results imply that careful consideration is required to choose the appropriate model for carrier-lattice coupling in such complex lattices.

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。

↑