Intermediate-Coupling Polaron Effective Mass

作者：David M. Larsen · 发表于：Physical Review · 年份：1968 · DOI：10.1103/physrev.174.1046 · 被引用次数：35 · 研究领域：Physics of Superconductivity and Magnetism、Atomic and Subatomic Physics Research、Advanced Frequency and Time Standards

We have calculated the polaron effective mass ${m}^{*}$ by extending the variational ansatz of a previous paper, where, in the Lee-Low-Pines representation, pair correlations between wave vectors of virtually emitted phonons are taken into account. Our results suggest that (1) effective masses calculated by fourth-order perturbation theory lie below the true values but are quite accurate for $\ensuremath{\alpha}<~3$ and (2) the Feynman theory gives effective masses which are somewhat too high in the intermediate-coupling region. For $\ensuremath{\alpha}\stackrel{\ensuremath{\sim}}{<}4.5$ we propose the estimate $\frac{{m}^{*}}{m}=1+\frac{\ensuremath{\alpha}}{6}+0.02363{\ensuremath{\alpha}}^{2}+0.0014{\ensuremath{\alpha}}^{3}$.