TY - JOUR
T1 - High temperature superconductivity induced by incipient magnetism
AU - Weger, M.
AU - Pereg, Y.
PY - 1990/10
Y1 - 1990/10
N2 - We consider the BCS gap equation, with an attractive interaction λ with an upper cutoff ω0 and lower cutoff ω1, and a repulsive interaction μ with cutoffΓ. We consider parameters such that a superconducting solution does not exist. We add a repulsive interaction ν eith cutoff ω1 (ω1 < ω0), and show that this repulsive interaction (that we attribute to incipient magnetism) induces a superconducting state possessing a high transition temperature. In this state, the gap function Δ(ε) oscillates as function of ε, with a period of order ω0. We also find solutions antisymmetric in energy [ Δ(ε) = - Δ(-ε) ], which turn out to be almost degenerate with the normal, symmetric ones. We discuss the physical implications of this model. Our model thus combines a low frequency repulsion due to antiferromagnetic interactions, with excitonic attraction at intermediate frequencies, and ordinary Coulomb repulsion above that. All frequency ranges, and coupling strengths, are comparable with the bandwidth.
AB - We consider the BCS gap equation, with an attractive interaction λ with an upper cutoff ω0 and lower cutoff ω1, and a repulsive interaction μ with cutoffΓ. We consider parameters such that a superconducting solution does not exist. We add a repulsive interaction ν eith cutoff ω1 (ω1 < ω0), and show that this repulsive interaction (that we attribute to incipient magnetism) induces a superconducting state possessing a high transition temperature. In this state, the gap function Δ(ε) oscillates as function of ε, with a period of order ω0. We also find solutions antisymmetric in energy [ Δ(ε) = - Δ(-ε) ], which turn out to be almost degenerate with the normal, symmetric ones. We discuss the physical implications of this model. Our model thus combines a low frequency repulsion due to antiferromagnetic interactions, with excitonic attraction at intermediate frequencies, and ordinary Coulomb repulsion above that. All frequency ranges, and coupling strengths, are comparable with the bandwidth.
UR - http://www.scopus.com/inward/record.url?scp=0025508824&partnerID=8YFLogxK
U2 - 10.1016/0038-1098(90)90294-L
DO - 10.1016/0038-1098(90)90294-L
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AN - SCOPUS:0025508824
SN - 0038-1098
VL - 76
SP - 39
EP - 48
JO - Solid State Communications
JF - Solid State Communications
IS - 1
ER -