Downfolding a quantum many-body system: the quasi-1D Fermi polaron

Fuente: arXiv
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Autori principali: Barišić, Lovro Anto, Orso, Giuliano, Chevy, Frédéric, Van Houcke, Kris
Natura: Preprint
Pubblicazione: 2025
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author Barišić, Lovro Anto
Orso, Giuliano
Chevy, Frédéric
Van Houcke, Kris
author_facet Barišić, Lovro Anto
Orso, Giuliano
Chevy, Frédéric
Van Houcke, Kris
contents We investigate the properties of an impurity immersed in an ensemble of spin-polarized fermions confined in a tight quantum wire. We use a non-perturbative variational approach that accounts for virtual transverse excitations and regularizes the zero-range interaction. We compute the polaron's energy, effective mass, and spectral weight, and benchmark our results against the exactly solvable Yang-Gaudin model of a purely 1D system. While the two models agree in the weakly interacting regime, we find significant deviations in the strongly attractive limit, including a divergence of the effective mass and evidence for a polaron-to-molecule transition inherited from the underlying 3D physics, which is absent in the purely 1D description. Our work quantifies the accuracy of quasi-1D systems as analog quantum simulators and highlights the emergence of beyond-1D physics even in nominally 1D settings.
format Preprint
id arxiv_https___arxiv_org_abs_2509_04934
institution arXiv
publishDate 2025
record_format arxiv
spellingShingle Downfolding a quantum many-body system: the quasi-1D Fermi polaron
Barišić, Lovro Anto
Orso, Giuliano
Chevy, Frédéric
Van Houcke, Kris
Quantum Gases
We investigate the properties of an impurity immersed in an ensemble of spin-polarized fermions confined in a tight quantum wire. We use a non-perturbative variational approach that accounts for virtual transverse excitations and regularizes the zero-range interaction. We compute the polaron's energy, effective mass, and spectral weight, and benchmark our results against the exactly solvable Yang-Gaudin model of a purely 1D system. While the two models agree in the weakly interacting regime, we find significant deviations in the strongly attractive limit, including a divergence of the effective mass and evidence for a polaron-to-molecule transition inherited from the underlying 3D physics, which is absent in the purely 1D description. Our work quantifies the accuracy of quasi-1D systems as analog quantum simulators and highlights the emergence of beyond-1D physics even in nominally 1D settings.
title Downfolding a quantum many-body system: the quasi-1D Fermi polaron
topic Quantum Gases
url https://arxiv.org/abs/2509.04934