The Holstein Polaron
The Holstein Polaron
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荷斯坦Polaron
DOI：
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发表时间：
1998
期刊：
影响因子：
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通讯作者：
I.Batistic
中科院分区：
文献类型：
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作者：
J. Bonca;S. Trugman;I.Batistic
我们描述了一种变分方法来解决的Holstein模型的电子耦合到动态，量子声子在一个无限的晶格。变分空间可以系统地扩展，以实现高精度与适度的计算资源（12位数精度的一维极化子能量在中间耦合）。我们计算地面和低洼激发态性质的模型在连续值的波矢$k$在基本上所有的参数制度。我们的结果的极化子能带，有效质量和相关函数相比，毫不逊色与其他数值技术，包括DMRG，全球本地和精确对角化。我们发现一个相变的第一激发态之间的束缚和非束缚系统的极化子和一个额外的声子激发。用强耦合微扰理论处理了相变。
We describe a variational method to solve the Holstein model for an electron coupled to dynamical, quantum phonons on an infinite lattice. The variational space can be systematically expanded to achieve high accuracy with modest computational resources (12-digit accuracy for the 1d polaron energy at intermediate coupling). We compute ground and low-lying excited state properties of the model at continuous values of the wavevector $k$ in essentially all parameter regimes. Our results for the polaron energy band, effective mass and correlation functions compare favorably with those of other numerical techniques including DMRG, Global Local and exact diagonalization. We find a phase transition for the first excited state between a bound and unbound system of a polaron and an additional phonon excitation. The phase transition is also treated in strong coupling perturbation theory.