Metal-insulator transitions and nanoscale phase separation in various underdoped cuprates

Abstract

We demonstrate that the unconventional electron-phonon interactions, charge inhomogeneity and charge ordering in underdoped cuprates play an important role in metal-insulator transitions and nanoscale phase separation. In so doing, we argue that charge carriers (i.e. hole polarons) in these systems segregate into insulating (carrier-poor) and metallic/superconducting (carrier-rich) regions as a result of their specific ordering. We show that the metal-insulator transitions, nanoscale phase separation and coexisting insulating and metallic/superconducting phases are manifested in the unusual temperature dependences of the magnetic susceptibility and resistivity and in the suppression of superconductivity in various underdoped cuprates.

Keywords

• underdoped cuprate superconductors
• phase separation
• magnetic susceptibility
• c -axis charge transport