Interface-induced $d$-wave pairing

We discuss a scenario for interface-induced superconductivity involving pairing by dipolar excitations proximate to a two-dimensional electron system controlled by a transverse electric field. If the interface consists of transition-metal oxide materials, the repulsive on-site Coulomb interaction is typically strong and a superconducting state is formed via exchange of nonlocal dipolar excitations in the $d$-wave channel. Perspectives to enhance the superconducting transition temperature are discussed.

Figure 1

(a) Geometry of the model system and the different interaction terms as described in text; (b), (c) Illustration of different interaction mechanisms leading to effective nonlocal electron pairing.

Figure 2

The critical temperature $T_{\mathrm{c}}$ as criterion for the interface mediated $d$-wave superconductivity is displayed as function of the external electric field energy $E_{\mathrm{ext}}$ for different values of the dipole energy gap ${\Delta }_{\mathrm{dp}}$.

Figure 3

Proposed realization of the L1/L2 model utilizing orthogonal atomic orbitals.