The interaction Hamiltonian for a dilute classical liquid of polarons à la Feynman in the presence of long-range Coulomb interaction is derived and the dielectric function is computed in mean field. Above a critical concentration the liquid becomes unstable. The onset of the instability is signaled by the softening of a collective optical mode in which all electrons oscillate in phase in their respective self-trapping potential. We associate the instability with a metalization of the system. Optical experiments in slightly doped cuprates and doped nickelates are analyzed within this theory. We discuss why doped cuprates metalize whereas nickelates do not.
Instability due to long-range Coulomb interaction in a liquid of Feynman polarons
Lorenzana J
2001
Abstract
The interaction Hamiltonian for a dilute classical liquid of polarons à la Feynman in the presence of long-range Coulomb interaction is derived and the dielectric function is computed in mean field. Above a critical concentration the liquid becomes unstable. The onset of the instability is signaled by the softening of a collective optical mode in which all electrons oscillate in phase in their respective self-trapping potential. We associate the instability with a metalization of the system. Optical experiments in slightly doped cuprates and doped nickelates are analyzed within this theory. We discuss why doped cuprates metalize whereas nickelates do not.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
