A look from the inside at high temperature superconductivity

High temperature superconductivity (HTSC) in cuprates, twenty years after discovery, remains one of the most challenging unresolved problems in modern condensed matter physics. It is known that mobile charge carriers in HTSC are confined to metallic CuO-planes, while non-metallic out-of-plane transport is achieved via interlayer tunneling. This leads to appearance of the “intrinsic” Josephson effect between neighboring CuO-planes below the superconducting transition temperature and provides a unique opportunity to probe bulk quasiparticle and phonon spectra inside HTSC single crystals.

I will give an overview of the current understanding and confusion in HTSC and of the experimental evidence for intrinsic Josephson effect in HTSC; show results of Intrinsic and Extrinsic(Surface) spectroscopy of HTSC; and discuss possible applications of intrinsic HTSC tunnel junctions.