Superconductivity and Coulomb Interaction 2: Gossamer Superconductor Properties

>>From Osher Doctorow mdoctorow@xxxxxxxxxxx

Across Zhang et al (2002), Yuan et al (2004), Won et al (2005),
Laughlin (2002), and Haas et al (2003), the following properties for
gossamer superconduction are found.

A. Temperature: high.
B. Superfluid density (very low (thin), unlike conventional
superconductors)
C. Chemical potential: higher than for RSV superconducting state of
doped Mott insulator
D. d-wave superconduction: high (dSC)
E. Spatially periodic dDW (analog of Fulde-Ferrell-Larkin-Ovchennikov
(CFFLO) state) stability: high
F. Proximity of antiferromagnetic phase: high (in Won et al)
G. Correlation: high (in Won et al)
H. Photoemission intensity of quasiparticle: low
I. Mott-Hubbard gap: low or incipient
J. Spectral weight of superconducting quasiparticle: very small
K. Heavy fermion systems: gossamer almost everywhere
L. Organic superconductors: gossamer almost everywhere
M. Specific Heat: low
N. Coulomb interaction (repulsion): different regimes for high and low
Coulomb interaction. Yuan et al find coexistence between AF
(antiferromagnetic) and dSC orders for low doping and large Coulomb
repulsion U, while gossamer superconductivity and low AF order is
characteristic of low U for low doping; the onsite interaction is
large, the intersite interaction is relatively small (repulsive) with
phase transition to Mott insulator as U increases at density 1 electron
per site). Laughlin considered Coulomb interaction to be high, as did
Zhang. Won found Coulomb dominance and interaction stronger than that
due to phonon exchange, which was taken for superconductors to mean
unconventional order parameters: d-waves, f-wave, g-wave
superconductors.
O. Doping: various levels, typically low but up to 0.5 or more in
various studies.
P. Uemera Relation: explained for low doping by gossamer theory which
can't be explained simply by other theories.

Osher Doctorow

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