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Four-particle condensate in strongly coupled fermion systems

G. Roepke·A. Schnell·P. Schuck·P. Nozieres
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Abstract

Four-particle correlations in fermion systems at finite temperatures are investigated with special attention to the formation of a condensate. Instead of the instability of the normal state with respect to the onset of pairing described by the Gorkov equation, a new equation is obtained which describes the onset of quartetting. Within a model calculation for symmetric nuclear matter, we find that below a critical density, the four-particle condensation (alpha-like quartetting) is favored over deuteron condensation (triplet pairing). This pairing-quartetting competition is expected to be a general feature of interacting fermion systems, such as the excition-biexciton system in excited semiconductors. Possible experimental consequences are pointed out.

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G. Roepke, A. Schnell, P. Schuck, P. Nozieres. 1998-03-26. Four-particle condensate in strongly coupled fermion systems. https://doi.org/10.1103/physrevlett.80.3177

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