Pseudogap-induced asymmetric tunneling in cuprate superconductors

Within the framework of the kinetic energy driven superconducting mechanism, the doping and temperature dependence of the asymmetric tunneling in cuprate superconductors is studied by considering the interplay between the superconducting gap and normal-state pseudogap. It is shown that the asymmetry of the tunneling spectrum in the underdoped regime weakens with increasing doping, and then the symmetric tunneling spectrum recovers in the heavily overdoped regime. The theory also shows that the asymmetric tunneling is a natural consequence due to the presence of the normal-state pseudogap.