Vortices wtih excitonic core in a system of two superconductors

We study the system of two layers: one doped with electrons and the other doped with holes, fully symmetrical upon the simultaneous electron-hole transformation and change of the layer. In each layer, an attractive interaction is established while between the layers normal electron-electron repulsion is present. We investigate a possibility of superconductivity within the layer accompanied by the exciton condensation between the layers. We show in the framework of the Landau-Ginsburg theory that such coexistence is, unlike the layer symmetrical case [1], is energetically unfavorable.

However, when a sufficiently strong external magnetic field is present, the formation of vortices in each superconductor may happen. Inside of the core of each of the vortices internal coherence is established. We study the transport and internal structure of such vortices and suggest experiments on how to check our predictions.

[1] Blinov, I. V., & MacDonald, A. H. (2022). Spatially Indirect Exciton Condensation in Superconductor Bilayers. arXiv preprint arXiv:2204.00438