Geometry dependence of the charge transfer at YBa2 Cu3 O7 -metal interfaces

Transport in electronic devices based on high- Tc superconductors depends critically on the charge redistribution at interfaces, since the band structure is modified on a local scale. Using the density functional theory approach for relaxed YBa2 Cu3 O7 -metal contacts, the charge transfer into the superconductor has been studied [U. Schwingenschlögl and C. Schuster, Appl. Phys. Lett. 90, 192502 (2007)]. In the present paper we discuss the systematics inherent in the local electronic structure of the near-contact YBa2 Cu3 O7 sites, in particular, the dependence on the contact geometry.