New type of antiferromagnetic polaron and bipolaron in HTc - superconductors

摘要

The possibility of formation of a new type of polaron based on the quantumaniferromagnet (AF) model is reported. We take into account exchangeinteractions between localized d-d spins of the AF, as well as the p-dinteraction of the AF with p-carriers. The energy minimum is found when maximum charge density occurs on everysecond spin. The formation of such ``comb''-like polarons results from thedamping of quantum fluctuations and the appearance of Van Vleck-like staggeredmagnetization. Such polarons tend to form pairs coupled by an AF ``glue''.