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A lattice pairing-field approach to ultracold Fermi gases
by Florian Ehmann, Joaquín E. Drut, Jens Braun
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Submission summary
| Authors (as registered SciPost users): | Jens Braun · Florian Ehmann |
| Submission information | |
|---|---|
| Preprint Link: | https://arxiv.org/abs/2212.12298v4 (pdf) |
| Date accepted: | 2024-03-04 |
| Date submitted: | 2023-11-21 13:11 |
| Submitted by: | Ehmann, Florian |
| Submitted to: | SciPost Physics |
| Ontological classification | |
|---|---|
| Academic field: | Physics |
| Specialties: |
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| Approaches: | Theoretical, Computational |
Abstract
We develop a pairing-field formalism for ab initio studies of non-relativistic two-component fermions on a $(d\!+\!1)$-dimensional spacetime lattice. More specifically, we focus on theories where the interaction between the two components can be described by the exchange of a corresponding pairing field. The introduction of a pairing field may indeed be convenient for studies of, e.g., the finite-temperature phase structure and critical behavior of, e.g., ultracold atomic Fermi gases. Moreover, such a formalism allows to directly compute the momentum and frequency dependence of the pair propagator, from which the pair-correlation function can be extracted. For a first illustration of the application of our formalism, we compute the density equation of state and the superfluid order parameter for a gas of unpolarized fermions in $(0\!+\!1)$ dimensions by employing the complex Langevin approach to surmount the sign problem.
List of changes
We have included remarks and references in the manuscript to reflect these comments:
1.- We added a reference to arXiv:1403.5680 on page 2 (left column, line 16-20, "We add that our ... see also Ref. [52] for a more general discussion.").
2.- In the right column of page 5, we have slightly adapted the sentence right below Eq. (36) and supplemented it with a footnote (see new footnote #3).
3.- We have adapted our general comments on the sign problem on page 6 (left column, line 4-14, "In this context, it is also ... with, e.g., Ref. [52]"), where also included five new references, see Refs. [52, 78-81].
4.- We have extended our discussion at the end of Subsec. IV.D., where we now comment on potential problems associated with singularities in the drift (see page 10, from line 9 in the left column to line 5 in the right column, "Beyond the expected ... treatment with the complex Langevin method."). Here, we also included six new references, see Refs. [89-94].
Additional change:
We have rephrased the sentence right above Eq. (32) to amend the column breaks on page 5.
Published as SciPost Phys. 16, 091 (2024)