Mass-gap description of heavy impurities in fermi gases
We present a unified theory that connects the quasiparticle picture of Fermi polarons for mobile impurities to the Anderson orthogonality catastrophe for static impurities. By operator reordering of the underlying many-body Hamiltonian, we obtain a modified fermionic dispersion relation that feature...
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| Main Authors: | , , , |
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| Format: | Article (Journal) |
| Language: | English |
| Published: |
6 November 2025
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| In: |
Physical review letters
Year: 2025, Volume: 135, Issue: 19, Pages: 1-7 |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/h2f7-dhjh |
| Online Access: | Verlag, lizenzpflichtig, Volltext: https://doi.org/10.1103/h2f7-dhjh Verlag, lizenzpflichtig, Volltext: https://link.aps.org/doi/10.1103/h2f7-dhjh 
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| Author Notes: | Xin Chen, Eugen Dizer, Emilio Ramos Rodríguez, and Richard Schmidt |
| Summary: | We present a unified theory that connects the quasiparticle picture of Fermi polarons for mobile impurities to the Anderson orthogonality catastrophe for static impurities. By operator reordering of the underlying many-body Hamiltonian, we obtain a modified fermionic dispersion relation that features a recoil-induced energy gap, which we call the “mass gap.” We show that the resulting mean-field Hamiltonian exhibits an in-gap state for finite impurity mass, which takes a key role in Fermi polaron and molecule formation. We identify the mass gap as the microscopic origin of the quasiparticle weight of Fermi polarons and derive a power-law scaling of the weight with the impurity-to-fermion mass ratio. The associated in-gap state is shown to give rise to the emergence of the polaron-to-molecule transition away from the limiting case of the Anderson orthogonality catastrophe in which the transition is absent. |
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| Item Description: | Veröffentlicht: 6. November 2025 Gesehen am 23.01.2026 |
| Physical Description: | Online Resource |
| ISSN: | 1079-7114 |
| DOI: | 10.1103/h2f7-dhjh |