Spectra of heavy polarons and molecules coupled to a Fermi sea

Dimitri Pimenov; Moshe Goldstein

doi:10.1103/physrevb.98.220302

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arXiv · 1809.02577

Spectra of heavy polarons and molecules coupled to a Fermi sea

Dimitri Pimenov·Moshe Goldstein

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Abstract

We study the spectrum of an impurity coupled to a Fermi sea (e.g., minority atom in an ultracold gas, exciton in a solid) by attraction strong enough to form a molecule/trion. We introduce a diagrammatic scheme which allows treating a finite mass impurity while reproducing the Fermi edge singularity in the immobile limit. For large binding energies the spectrum is characterized by a semi-coherent repulsive polaron and an incoherent molecule-hole continuum, which is the lowest-energy feature in the single-particle spectrum. The previously predicted attractive polaron seems not to exist for strong binding.

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Dimitri Pimenov, Moshe Goldstein. 2018-09-07. Spectra of heavy polarons and molecules coupled to a Fermi sea. https://doi.org/10.1103/physrevb.98.220302

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