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arXiv · 1201.5816

Electron-hole pair condensation at the semimetal-semiconductor transition: a BCS-BEC crossover scenario

B. Zenker·D. Ihle·F. X. Bronold·H. Fehske
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Abstract

We act on the suggestion that an excitonic insulator state might separate---at very low temperatures---a semimetal from a semiconductor and ask for the nature of these transitions. Based on the analysis of electron-hole pairing in the extended Falicov-Kimball model, we show that tuning the Coulomb attraction between both species, a continuous crossover between a BCS-like transition of Cooper-type pairs and a Bose-Einstein condensation of preformed tightly-bound excitons might be achieved in a solid-state system. The precursor of this crossover in the normal state might cause the transport anomalies observed in several strongly correlated mixed-valence compounds.

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B. Zenker, D. Ihle, F. X. Bronold, H. Fehske. 2012-03-19. Electron-hole pair condensation at the semimetal-semiconductor transition: a BCS-BEC crossover scenario. https://doi.org/10.1103/physrevb.85.121102

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