ELECTRON STRINGS IN OXIDES

We found that insulating and conducting electron strings may arise in oxide materials with not very wide bands, like HTSC, due to electron-phonon and electron-electron interactions including antiferromagnetic correlations. We estimate the string length and the number of particles self-trapped into a single string taking into account the typical parameters of cuprates, like La₂CuO₄. The conducting strings typically may have a small doping (n<0.3) and are created mostly due to the long-range electron-phonon interaction associated with ionic bonding of Oxides.