Electronic vibrons and possible mechanism for high-temperature superconductivity

Abstract

We show that electronic molecules, i.e. bound configurations of electrons within solids, have vibronic modes, which we call electronic vibrons. We derive an analytic expression for the frequency of these vibrons. Our estimation of this frequency made for typical parameters of metallic oxides gives the value of the order 10 −15 -10 −14 s. Here we show that these vibrons may play an important role in the possible mechanism for a high-temperature superconductivity. We find also that the highest critical temperature for high-temperature superconductivity will have solids with strong electron-vibron coupling (for strongly correlated electrons when the screening is not very strong) and with intermediate electron-phonon coupling. Numerous experimental data in cuprates (an isotope effect, pseudo-gap and a stripe formation) are consistent with the new mechanism.

Dilution and clustering of Fe in the rutile phases ofTiO2andSnO2

“…According to this model, 37 we have determined the "phonon cloud," more exactly just the partial contribution of 57 Fe into it, capable to trap a few electrons into a stringlike or planar configuration and create a stable or metastable cluster of electrons. Interestingly, the electrons trapped into the electron cluster could mediate the superconducting coupling among itinerant carriers in high-T c superconductors 38 via exchange by their high-frequency electronic intramolecular vibrational modes, termed vibrons. Magnetic exchange among localized moments could be another consequence of the high-frequency vibronic states in thus created electronic molecules.…”

Bond-length fluctuations in the copper oxide superconductors

“…Kusmartsev [233] has extended the bipolaron concept of Alexandrov to consider vibronic modes within an 'electronic molecule', which he considers to be a small bipolaron. However, the concept can be generalized to include a two-electron/two-hole correlation bag.…”