Mechanical stability of resonant Bose-Fermi mixtures

We investigate the mechanical stability of Bose-Fermi mixtures at zero temperature in the presence of a tunable Feshbach resonance, which induces a competition between boson condensation and boson-fermion pairing when the boson density is smaller than the fermion density. Using a many-body diagramma...

Full description

Saved in:
Bibliographic Details
Main Author: Christian Gualerzi, Leonardo Pisani, Pierbiagio Pieri
Format: Article
Language:English
Published: SciPost 2025-08-01
Series:SciPost Physics
Online Access:https://scipost.org/SciPostPhys.19.2.039
Tags: Add Tag
No Tags, Be the first to tag this record!
_version_ 1849239417442533376
author Christian Gualerzi, Leonardo Pisani, Pierbiagio Pieri
author_facet Christian Gualerzi, Leonardo Pisani, Pierbiagio Pieri
author_sort Christian Gualerzi, Leonardo Pisani, Pierbiagio Pieri
collection DOAJ
description We investigate the mechanical stability of Bose-Fermi mixtures at zero temperature in the presence of a tunable Feshbach resonance, which induces a competition between boson condensation and boson-fermion pairing when the boson density is smaller than the fermion density. Using a many-body diagrammatic approach validated by fixed-node Quantum Monte Carlo calculations and supported by recent experimental observations, we determine the minimal amount of boson-boson repulsion required to guarantee the stability of the mixture across the entire range of boson-fermion interactions from weak to strong coupling. Our stability phase diagrams indicate that mixtures with boson-to-fermion mass ratios near two, such as the $^{87}$Rb-$^{40}$K system, exhibit optimal stability conditions. Moreover, by applying our results to a recent experiment with a $^{23}$Na-$^{40}$K mixture, we find that the boson-boson repulsion was insufficient to ensure stability, suggesting that the experimental timescale was short enough to avoid mechanical collapse. On the other hand, we also show that even in the absence of boson-boson repulsion, Bose-Fermi mixtures become intrinsically stable beyond a certain coupling strength, preceding the quantum phase transition associated with the vanishing of the bosonic condensate. We thus propose an experimental protocol for observing this quantum phase transition in a mechanically stable configuration.
format Article
id doaj-art-ebc9865cb8874c79bf36328c3a7553e7
institution Kabale University
issn 2542-4653
language English
publishDate 2025-08-01
publisher SciPost
record_format Article
series SciPost Physics
spelling doaj-art-ebc9865cb8874c79bf36328c3a7553e72025-08-20T04:01:01ZengSciPostSciPost Physics2542-46532025-08-0119203910.21468/SciPostPhys.19.2.039Mechanical stability of resonant Bose-Fermi mixturesChristian Gualerzi, Leonardo Pisani, Pierbiagio PieriWe investigate the mechanical stability of Bose-Fermi mixtures at zero temperature in the presence of a tunable Feshbach resonance, which induces a competition between boson condensation and boson-fermion pairing when the boson density is smaller than the fermion density. Using a many-body diagrammatic approach validated by fixed-node Quantum Monte Carlo calculations and supported by recent experimental observations, we determine the minimal amount of boson-boson repulsion required to guarantee the stability of the mixture across the entire range of boson-fermion interactions from weak to strong coupling. Our stability phase diagrams indicate that mixtures with boson-to-fermion mass ratios near two, such as the $^{87}$Rb-$^{40}$K system, exhibit optimal stability conditions. Moreover, by applying our results to a recent experiment with a $^{23}$Na-$^{40}$K mixture, we find that the boson-boson repulsion was insufficient to ensure stability, suggesting that the experimental timescale was short enough to avoid mechanical collapse. On the other hand, we also show that even in the absence of boson-boson repulsion, Bose-Fermi mixtures become intrinsically stable beyond a certain coupling strength, preceding the quantum phase transition associated with the vanishing of the bosonic condensate. We thus propose an experimental protocol for observing this quantum phase transition in a mechanically stable configuration.https://scipost.org/SciPostPhys.19.2.039
spellingShingle Christian Gualerzi, Leonardo Pisani, Pierbiagio Pieri
Mechanical stability of resonant Bose-Fermi mixtures
SciPost Physics
title Mechanical stability of resonant Bose-Fermi mixtures
title_full Mechanical stability of resonant Bose-Fermi mixtures
title_fullStr Mechanical stability of resonant Bose-Fermi mixtures
title_full_unstemmed Mechanical stability of resonant Bose-Fermi mixtures
title_short Mechanical stability of resonant Bose-Fermi mixtures
title_sort mechanical stability of resonant bose fermi mixtures
url https://scipost.org/SciPostPhys.19.2.039
work_keys_str_mv AT christiangualerzileonardopisanipierbiagiopieri mechanicalstabilityofresonantbosefermimixtures