Coexistence of dielectric and superconductive ordering in two-band systems

A study is made of the coexistence of dielectric and superconducting phases in two-band systems when one of the bands is fiat. Allowance is made for the departure from half filling of a one-dimensional band, $\mu\ne0$ ($\mu$ is the chemical potential), and also jump processes. It is found that a superconducting state can be generated on the background of a dielectric state in the two-band system. However, the formation of a dielectric state on the background of superconductive ordering is impossible at all values of $\mu$, i.e., superconductivity prevents the dielectric transition.