Table 2 Coupling energies \(\Delta\) for \(U=0\) for a discrete model \(\Delta ^d\), for continuum Holstein model \(\Delta ^H\), and translation invariant bipolaron \(\Delta ^{TI}\)
From: A translation invariant bipolaron in the Holstein model and superconductivity
\(\Delta\) | \(\kappa\) | ||||
|---|---|---|---|---|---|
0.1 | 0.1975 | 0.296 | 0.359 | 0.5267 | |
\(\Delta ^d\) | 0.0037 | 0.015 | 0.05 | 0.112 | 0.203 |
\(\Delta ^H\) | 0.0037 | 0.0145 | 0.033 | ||
\(\Delta ^{TI}\) | 0.0056 | 0.022 | 0.0495 | ||