Electrical characterization of YBCO single crystal surfaces oriented in any crystallographic direction

Abstract

Although considerable studies have been carried out, the true nature of high-Tc superconductors (HTCS) is still not clear. Pseudogap phase at high temperature as well as possible time reversal symmetry breaking at low temperature need further investigations. The need of carefully made samples showing the intrinsic properties of superconductivity is essential to test new theoretical developments. We present in this paper how to control crystallographic orientation in the junction and a technique developed to determined the quality of the interface barrier between a gold electrode and a HTCS : YBCO. This potentially allows us to perform Andreev spectroscopy in the CuO2 planes of cuprate superconductors as a function of temperature, crystallographic orientation and doping.