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arXiv · 0804.2638

Normal state of highly polarized Fermi gases: Full many-body treatment

R. Combescot·S. Giraud
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Abstract

We consider a single \down atom within a Fermi sea of \up atoms. We elucidate by a full many-body analysis the quite mysterious agreement between Monte-Carlo results and approximate calculations taking only into account single particle-hole excitations. It results from a nearly perfect destructive interference of the contributions of states with more than one particle-hole pair. This is linked to the remarkable efficiency of the expansion in powers of hole wavevectors, the lowest order leading to perfect interference. Going up to two particle-hole pairs gives an essentially perfect agreement with known exact results. Hence our treatment amounts to an exact solution of this problem.

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R. Combescot, S. Giraud. 2008-04-16. Normal state of highly polarized Fermi gases: Full many-body treatment. https://doi.org/10.1103/physrevlett.101.050404

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