A route to small Drude weight in metals with nested spin fluctuations and enhanced impurity scattering associated with quantum critical phenomena

Abstract

It is discussed that the small Drude weight D observed in high- T c cuprates is compatible with the small renormalization amplitude z and not enhanced effective mass m ∗ of quasiparticles even in the framework of Fermi liquid theory. In particular, such a situation is expected if the Fermi surface of quasiparticle is nested as expected near the magnetic metal–insulator transition point. It is also discussed that the quantum critical fluctuations give rise to enhancement of impurity potential through the vertex correction of scattering leading to enhancement of “residual resistivity”. Two cases, physically interesting, are discussed: (1) non-magnetic impurity scattering near the ferromagnetic critical point and (2) non-magnetic impurity near the charge density critical point. The latter case has some relevance to the reduction of superconducting transition temperature of high- T c cuprates in the underdoped region.