Processes in HTS Josephson junctions

The current status of understanding the physics of HTS Josephson junctions are reviewed with the focus on SNS devices and structures with the interlayers formed by semiconductor-oxide materials. Recent results of investigations transport properties of HTS/Au interfaces are discussed. It is shown that the Y BCO (001)/Au interface can be considered as a set of constrictions with better transparency via which the gold contacts to ab-planes of the electrode. The main consequences follows from the interface model for the description the processes in edge type SNS HTS Josephson junctions are discussed. The data obtained in HTS junctions with semiconductor oxide interlayers are also briefly reviewed.