Mesoscopic josephson junctions of high-Tcsuperconductors

Abstract

In this paper we examine the state-of-the-art patterning techniques for fabrication of ultrasmall bicrystal Josephson junctions in ${\mathrm{YBa}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{x}.$ We determine the dependence of junction parameters---critical current, characteristic voltage ${I}_{c}{R}_{n},$ and capacitance---on its size. Using the values of the Josephson and the Coulomb energies extracted from experiment, we analyze the dynamics of the junction in zero-bias quantum regime. Finally, we discuss the relevance of parameters, obtained from transport measurements, for the decoherence time in the system.