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BCS theory for s+g-wave superconductivity borocarbides Y(Lu)Ni$_2$B$_2$C

Qingshan Yuan·Peter Thalmeier
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Abstract

The s+g mixed gap function Δ_k=Δ{[(1-x)-x\sin^4θ\cos4ϕ]} (x: weight of g-wave component) has been studied within BCS theory. By suitable consideration of the pairing interaction, we have confirmed that the coexistence of s- and g-wave, as well as the state with equal s and g amplitudes (i.e., x=1/2) may be stable. This provides the semi-phenomenological theory for the s+g-wave superconductivity with point nodes which has been observed experimentally in borocarbides YNi_2B_2C and possibly in LuNi_2B_2C.

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Qingshan Yuan, Peter Thalmeier. 2003-01-16. BCS theory for s+g-wave superconductivity borocarbides Y(Lu)Ni$_2$B$_2$C. https://doi.org/10.1103/physrevb.68.174501

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