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Vector Cooper Pairs and Coherent-Population-Trapping-like States in Ensemble of Interacting Fermions

A. V. Taichenachev·V. I. Yudin
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Abstract

Using the standard Hamiltonian of the BCS theory, we show that in an ensemble of interacting fermions with the spin 1/2 there exist coherent states $|NC>$, which nullify the Hamiltonian of the interparticle interaction (scattering). These states have an analogy with the well-known in quantum optics the coherent population trapping (CPT) effect. The structure of these CPT-like states corresponds to Cooper pairs with the total spin $S$=1. The found states have a huge degree of degeneracy and carry a macroscopic magnetic moment, that allows us to construct a new model of the magnetism connected with the delocalized electrons in metals (conductors). A principal possibility to apply the obtained results to the superfluid $^3$He is also demonstrated.

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A. V. Taichenachev, V. I. Yudin. 2008-02-18. Vector Cooper Pairs and Coherent-Population-Trapping-like States in Ensemble of Interacting Fermions. https://doi.org/10.1140/epjd%2Fe2008-00115-2

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