Superconductivity in Engineered Two-Dimensional Electron Gases

Abstract

We consider Kohn-Luttinger mechanism for superconductivity in a two-dimensional electron gas confined to a narrow well between two metallic planes with two occupied subbands with Fermi momenta $k_{FL}>k_{FS}$. On the basis of a perturbative analysis, we conclude that non-s-wave superconductivity emerges even when the bands are parabolic. We analyze the conditions that maximize $T_c$ as a function of the distance to the metallic planes, the ratio $k_{FL}/k_{FS}$, and $r_s$, which measures the strength of Coulomb correlations. The largest attraction is in p-wave and d-wave channels, of which p-wave is typically the strongest. For $r_s=O(1)$ we estimate that the dimensionless coupling $\lambda \approx 10^{-1}$, but it likely continues increasing for larger $r_s$ (where we lose theoretical control).

6 pages, 4 figures

References in corpus (2)

• Superconductivity in the repulsive Hubbard model: an asymptotically exact weak-coupling solution
• s-wave Superconductivity Phase Diagram in the Inhomogeneous Two-Dimensional Attractive Hubbard Model