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arXiv · 1508.00508

Excitonic gap formation in neutral bilayer structures

V. Apinyan·T. K. Kopeć
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Abstract

We consider the pairing between conduction band electrons, and the valence band holes in the neutral bilayer-type structures. By employing the bilayer Hubbard model, we show the possibility of the inter-plane exciton formation in the system without applied external field. The in-plane and inter-plane Coulomb interaction effects on the pairing mechanism are considered, and the role of the in-plane particle hopping asymmetry on the gap behavior is analyzed in the paper. We show that both Frenkel-type pairing channel and Wannier-Mott-type excitonic pairings are present in the considered system. We analyze also the structure of the chemical potential in the bilayer system. The temperature effects, and the tunable inter-plane electron hopping effects are discussed. For the Frenkel channel, we have shown a particular behavior of the chemical potential at the very low temperatures, which is related to the degenerated Frenkel-gap.

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V. Apinyan, T. K. Kopeć. 2015-08-03. Excitonic gap formation in neutral bilayer structures. https://doi.org/10.1088/0031-8949%2F90%2F8%2F085806

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