in a composite superconducting-metallic two-component model.*

Can we realize enhanced T_c in a low superfluid density superconductor by coupling it to a metal? This idea, which was postulated in [1] and shown perturbatively in [2], suggests that coupling a layer with a large pairing scale Δ₀ but small phase stiffness to a non-interacting metallic layer can raise T_c to its mean-field value T_MF =Δ₀/2. We studied this system nonperturbatively using the dynamical cluster approximation for a 2D attractive Hubbard model coupled to a noninteracting metallic layer via interlayer hopping. In contrast to prior work, our results for T_c appear only to decrease with increasing interlayer coupling.

[1] S. A. Kivelson, Physica B (Amsterdam) 11, 61 (2002)
[2] E. Berg et al., Phys. Rev. B 78, 0904509 (2008)