论文标题
PEIERLS与荷斯坦模型，用于描述钙钛矿中的电子音波耦合
Peierls versus Holstein models for describing electron-phonon coupling in perovskites
论文作者
论文摘要
我们将动量平均近似值与适当限制的扰动方法一起研究，以在受BABIO3启发的钙钛矿晶格上研究单个极性物理。我们研究了PEIERLS类型的电子 - 音波耦合，从而使离子的运动调节位点之间的跳跃积分的值，并表明它不能映射到整个参数空间中较简单的一波段霍尔斯坦模型上。这是因为Peierls Polaron的分散体具有急剧的转变，在Brillouin区域的高对称点之间，地下动量跳跃，而Holstein Polaron始终具有相同的地下动量。这些结果表明，需要仔细考虑在如此复杂的晶格中选择适当的载体晶格耦合模型。
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.
