Phonon electron coupling energies from

Electron-Phonon Coupling Energies and Frequencies from Experi-mental Data... 

Low-temperature oxygen ion irradiations of various elemental superconductors show a minimum in the Tc vs. dose curve, and a subsequent increase in Tc at higher doses. In Nb this decrease is attributed to the decrease in the energy gap anisotropy with the increase attributed to strain (which changes the electron-phonon coupling) resulting from defect agglomeration. 

Similar to the case of transition to supersonic velocities discussed above, this interchain transport process is also nonadiahatic. To pass through the barrier, the electron has to undergo an electronic transition from the polaron level localized to chain 1 to the TT -level localized to chain 2. The energy needed for this transition, the activation energy, is taken from the phonon system. Actually, the process is very similar to that treated by the Holstein theory discussed in Section 2.2 the electronic coupling between the chains is weak enough to force the electronic states to localize on individual chains. 

The first term on the right-hand side of eqn (7.1) is just the electron-phonon coupling arising from the change in the kinetic energy, which is the first term in... 

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