Authors
Abstract
Two decades ago the epoch making discovery of high Tc cuprate superconductivity by Bednorz and Müller shocked the world’s superconductivity community. However, already in 1979 and 1980, the first heavy fermion superconductor CeCu2Si2 and organic superconductor (TMTSF)2PF6 have been discovered respectively. Also we know now that all these superconductors are unconventional and nodal. Further the quasiparticles in the normal state in these systems are Fermi liquids and the superconducting states are described in terms of generalized BCS wave function. Also the pseudogap phase in underdoped high Tc cuprates is described in terms of d-wave density wave. This implies necessarily that the superconductivity in underdoped cuprates is gossamer (i.e. d-wave superconductivity coexists with d-wave density wave). We shall present some quantitative tests of these new concepts, notions and ideas.
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