Tunnelling Measurements As A New Method Of Investigation Of Thin Film Superconducting Cuprate Junctions
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293 - 305
Tunnelling measurements in thin film superconducting junctions involving cuprates (like YBa2Cu3O7 or La2-xCexCuO4-y) are emerging as a unique tool of investigation. Thus, looking into tunnelling of Cooper pairs (the current that flows with no resistance) or quasiparticles in specially designed junctions is the most reliable method to investigate the symmetry of the superconducting order parameter in cuprates. This is crucial to establish a pairing mechanism for the electrons, i.e., the formation of Cooper pairs in these materials - one of the most important unsolved problems in modern solid state physics. Then, a detailed investigation of both dc and ac tunnelling of Cooper pairs in these junctions is essential to determine the current-phase relation (the relation between the current and the phase of the superconducting condensate). This represents a key element required in many applications like low-dissipative superconducting electronics or superconducting qubits in quantum computation. Also, tunnelling of quasiparticles in these junctions represent an accurate new method to determine the second critical field of cuprates. Here an overview on all these fundamental and applied aspects of this interesting class of nano materials will be given. Keywords: unconventional superconductivity, thin film superconducting cuprate junctions, low temperature electric transport measurements.
unconventional superconductivity, thin film superconducting cuprate junctions, low temperature electric transport measurements