Tunneling-driven quantum phase transitions in mesoscopic commensurate Systems

摘要

We demonstrate here that new phenomena can occur in mesoscopic commensurate systems of strongly correlated electrons: tunneling-driven quantum phase transitions. To exemplify, we present CDW-to-CDW (SDW-to-SDW) transitions between charge (spin) density wave states of different symmetries in quantum rings described by an extended Hubbard model. These transitions can be studied experimentally e.g. by optical absorption.