Pith. sign in

REVIEW 2 major objections 4 minor 40 references

Energetic and Structural Properties of Two-Dimensional Trapped Mesoscopic Fermi Gases

T0 review · 2 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

Pith's one-line read This paper provides numerically exact energy spectra and pairing correlations for two, four, and six trapped fermions in two dimensions, showing that binding energies up to $2\hbar\omega_r$ lie outside the regime of tightly bound…

desk verdict Careful and useful 2D few-fermion reference data, but the finite-effective-range pairing claim rests on a quasi-2D mapping whose error is never quantified. read the letter →

arxiv 2506.20891 v1 pith:SN66AQIZ submitted 2025-06-25 cond-mat.quant-gas

classification cond-mat.quant-gas
keywords mesoscopicFermigasestwo-dimensionalgasquasi-2DconfinementeffectiverangecorrelatedGaussianbasisstochasticvariationalmethodpairingcorrelationsfew-bodyphysics
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper asks what happens to small, spin-balanced Fermi gases in a two-dimensional harmonic trap as the attraction between opposite spins grows. Using a numerically exact stochastic variational calculation on a correlated Gaussian basis, it computes the ground- and low-lying excited-state energies, natural-orbital occupations, momentum distributions, and radial correlation functions for gases containing one, two, or three atoms per spin state, parameterised by the 2D scattering length and effective range. The central result is that for up to six particles at zero effective range, binding energies up to about $2\hbar\omega_r$ never reach the regime of tightly bound bosonic molecules. At a fixed binding energy, moving from strictly 2D to quasi-2D confinement, which corresponds to a finite negative effective range, enhances the pairing correlations. This gives a theoretical map of few-fermion physics that modern cold-atom experiments can realise and test.

What carries the argument

The machinery is the two-dimensional effective-range expansion, $\cot[\delta(k)] = (2/\pi)[\gamma + \ln(ka_{2D}/2)] + (1/\pi) k^2 r_{2D} + \cdots$, which reduces all short-range interaction details to the scattering length $a_{2D}$ and effective range $r_{2D}$. A finite-range Gaussian potential is tuned so that its width stays small, $r_0 \lesssim 0.1 l_r$, making higher-order terms negligible, and quasi-2D confinement is encoded through the mapping $r_{2D} = -l_z^2 \ln(2)$. The $N$-body Schrödinger equation is then solved by expanding the relative wave function in explicitly correlated Gaussian basis states with stochastically optimised width parameters, which allows numerically exact extraction of density matrices and their analytical Fourier transforms.

What would settle it

Compute the same few-body observables for two different short-range potentials that share the same 2D scattering length and effective range; if the energies or pair distributions differ systematically, the effective-range truncation used here is not sufficient.

Watch

Extended reading notes

Core claim

On the paper's own terms, the discovery is a complete numerical characterisation of trapped two-dimensional Fermi gases with $1+1$, $2+2$, and $3+3$ particles, including low-lying monopole spectra, one- and two-body density matrices, natural-orbital occupation numbers, atom and pair momentum distributions, and radial pair distribution functions. The key finding is that even at the strongest binding energies converged, $\epsilon_b \approx 2\hbar\omega_r$, the opposite-spin pair correlations have not developed the tight composite-boson structure of the deep BEC limit: the pair distribution function still shows a broad dimer-dimer peak, and the one-body density matrix can be reconstructed from only a handful of natural orbitals. Adding a finite, negative effective range, the signature of quasi-2D confinement, increases the short-distance molecular peak and lowers the occupation of the lowest natural orbitals at fixed $\epsilon_b$, so pairing is stronger in quasi-2D geometry. The paper also reports that the molecular "condensate fraction" extracted from the reduced two-body density matrix is non-monotonic in $\epsilon_b$ and has limited interpretability for such small systems.

Load-bearing premise

The calculations assume that the short-range interaction is fully described by the 2D scattering length and effective range, so that the detailed shape of the interatomic potential never matters at the trap energies studied.

Editorial extensions

If this is right

  • The energy spectra for $1+1$, $2+2$, and $3+3$ fermions provide finite-system benchmarks that can be compared directly with deterministic few-atom experiments and with extrapolations toward many-body 2D Fermi gas theories.
  • For binding energies $\epsilon_b \lesssim 2\hbar\omega_r$, the one-body density matrix is accurately decomposed into at most the six lowest natural orbitals, so few-body pairing in this regime is describable by a small effective single-particle Hilbert space.
  • At fixed $\epsilon_b$, a more negative effective range, corresponding to stronger quasi-2D confinement, shifts energies upward, strengthens the short-distance peak of the pair distribution function, and lowers the lowest natural-orbital occupations, meaning confinement promotes molecule formation without changing the momentum distributions.
  • The non-monotonic "condensate fraction" defined from the reduced two-body density matrix is not a reliable order parameter for these small systems, so molecular condensation in 2D few-fermion gases should be diagnosed through pair distribution functions and pair momentum distributions instead.
  • Because the method cannot converge for $3+3$ fermions at binding energies above about $2\hbar\omega_r$, the deep BEC side of the crossover remains an open target for other few-body techniques.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • A direct experimental test would be to measure the pair momentum distribution $n(K)$ and the real-space pair distribution in a quasi-2D microtrap with two to twelve atoms while varying the axial confinement; the paper's results predict that $n(K)$ changes very little with binding energy, but the short-distance pair peak grows as the effective range becomes more negative.
  • Because the correlated Gaussian approach fails to converge for $\epsilon_b > 2\hbar\omega_r$ in the six-fermion case, the paper leaves open whether the non-monotonic condensate fraction turns over and approaches unity at stronger coupling; alternative few-body methods could probe this part of the crossover.
  • The strong effect of effective range at fixed binding energy suggests a practical tuning route for experiments: changing the trap aspect ratio may mimic changing the interaction strength even when the scattering length is held fixed.
Share X Bluesky LinkedIn Reddit HN

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

2 major / 4 minor

Summary. This manuscript studies equal-mass spin-balanced two-component Fermi gases with two, four, and six atoms confined in a two-dimensional harmonic trap, interacting via a short-range Gaussian potential parameterized by the 2D scattering length and effective range. Using the explicitly correlated Gaussian method with stochastic variational optimization, the authors compute ground- and low-lying monopole energy spectra as functions of the two-body binding energy, natural-orbital occupation numbers from one- and reduced two-body density matrices, a molecular condensate fraction, momentum distributions of atoms and pairs, and radial and pair distribution functions. Benchmarks are provided against the Busch spectrum for 1+1 fermions and against analytical results for the non-interacting 2+2 system in Appendix A. The main physical conclusions are that for up to six atoms at binding energies eps_b <~ 2 hbar omega_r the gas remains outside the tightly bound molecular regime, and that at fixed binding energy a finite negative effective range, representing quasi-2D confinement, enhances pairing.

Significance. If the results hold, this paper provides a useful two-dimensional counterpart to the established three-dimensional few-fermion studies of Blume and co-workers, with direct relevance to ongoing mesoscopic Fermi-gas experiments. The strengths are the use of an established numerical method, explicit checks against exact analytic limits, self-contained calculations with no fitted observables, and an analytic Fourier transform of the density matrices that makes momentum-space observables cheap to evaluate. The paper is also candid about the limitations of the ECG approach for larger atom numbers and deeper binding. The main uncertainty is the quantitative validity of the quasi-2D effective-range mapping at the largest binding energies considered, which is load-bearing for the central claim about enhanced pairing at fixed binding energy; this needs to be addressed before the finite-effective-range results can be taken as universal rather than as artifacts of truncation of the mapping.

major comments (2)
  1. [Section 2, Eq. (5); Section 3.5, Figs. 6-9] The central comparison between r2D/lr^2 = -0.2 and approximately zero is made without quantifying the error of the quasi-2D mapping in Eq. (5). This mapping is derived for klz << 1, but at the largest binding energies plotted, eps_b ~ 2 hbar omega_r, the relative momentum is k ~ sqrt(2)/lr, so with lz/lr = sqrt(0.2/ln 2) ~ 0.54 one obtains klz ~ 0.76. Higher-order confinement corrections of order (klz)^2 ~ 0.6 are then comparable to the effective-range term (1/pi)k^2 r2D ~ -0.06, and the next-order shape parameter is not computed. The condition r0 <= 0.1 lr controls only the short-range shape of the two-dimensional model potential and does not test the accuracy of the quasi-2D projection. I therefore request an explicit estimate of the omitted confinement corrections, or a restriction of the finite-range comparison to binding energies where klz is demonstrably small.
  2. [Section 3.1 and Section 4] The manuscript reports no convergence residuals, basis-size dependence, or error bars for the energies or the derived structural observables. The text states that convergence cannot currently be achieved for six atoms at eps_b > 2 hbar omega_r, yet the spectra and structural results extend to eps_b ~ 2.1 hbar omega_r, and the central conclusion that eps_b <~ 2 hbar omega_r lies outside the strong-interaction regime relies on data in this region. Please add a quantitative convergence statement for the 3+3 states near the upper end of the range (for example, energy change with basis size or an extrapolated value) and indicate how the uncertainty propagates to the occupation numbers, momentum distributions, and distribution functions.
minor comments (4)
  1. [Eq. (31)] The displayed equality [n_up(k)]_AA' == [n_up(k)]_AA' is a typo; the left-hand side should presumably be defined as the matrix element and the right-hand side as the closed-form expression c1/(g1 g4) exp(k^2/(2 g4)).
  2. [Eq. (35b)] The text states that V(rk - rl) = delta(r - rk - rl) is substituted into Eq. (35b), but the argument of the delta function should be r - (rk - rl); please correct the sign.
  3. [Section 3.2.3, Eqs. (21)-(22)] The definition of the condensate fraction is not fully explicit about the set over which the maximum is taken: Eq. (22a) includes the n=1,m=0 term while the surrounding text says the sum applies for m > 0. Please state the complete summation rule.
  4. [Fig. 1 caption] The caption reads 'at very nearly zero effective' and appears to be missing the word 'range'; please correct.

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity: the calculations are self-contained, benchmarked against independent analytical results, and no observable is fitted to the target conclusions.

full rationale

The paper's derivation chain is not circular. The interaction model is a finite-range Gaussian potential with parameters V0 and r0, which are converted into the two-body scattering length a2D and effective range r2D by fitting the free-space phase shift to Eq. (4). The two-body binding energy eps_b is then computed from the 1+1 trapped relative ground-state energy, and all reported many-body energies and structural quantities are obtained by solving the N-body Hamiltonian (1) with the ECG/stochastic variational method. None of the reported observables is used as an input or fit target; the comparison at fixed eps_b between r2D approximately 0 and r2D = -0.2 is a genuine prediction of the model. The 1+1 spectrum is checked against the analytically known Busch spectrum, and the 2+2 non-interacting occupation numbers are reproduced analytically in Appendix A, providing external benchmarks. The main self-citations are to Ref. [11] for ECG matrix elements and for the potential parametrization used there; these are method-level references to a standard technique (Refs. [12-15]) and are not the load-bearing justification for the physics conclusions. The quasi-2D mapping r2D = -lz^2 ln(2) is attributed to external works [21-24]; whether its regime of validity extends to the largest |r2D| used is a quantitative accuracy concern, not a circularity. Accordingly, no circular step is identified; the score of 2 merely acknowledges minor method-level self-citation without making the central claim depend on it.

Assumptions & free parameters 3 free parameters · 4 assumptions · 0 invented entities

The central results rest on the 2D effective-range theory, the quasi-2D mapping r2D = -l2_z ln(2), and the variational completeness of the ECG basis. No genuinely new entities are introduced; the 'condensate fraction' indicator is imported from Blume-Daily [25]. The free parameters are model inputs tuned to realize the desired scattering properties, not fitted to the reported observables.

free parameters (3)
  • V0 (Gaussian potential depth) = not specified; varied to realize target binding energies
    The Gaussian depth V0 is tuned to produce a chosen two-body binding energy eps_b; it is an input parameter, not fitted to many-body data.
  • r0 (Gaussian width) = r0 <= 0.1 lr
    Chosen small enough that the effective-range expansion (4) is dominated by a2D and r2D; it sets the short-range physics.
  • r2D (effective range parameter) = -0.001 lr^2 and -0.2 lr^2
    The two values used to mimic strictly 2D and quasi-2D confinement; chosen based on the mapping in Eq. (5).
assumptions (4)
  • domain assumption The two-body low-energy scattering in 2D is universally determined by a2D and r2D, with higher-order terms negligible for r0 <= 0.1 lr (Section 2).
    This is the universality assumption of effective-range theory; the paper checks that widths are small but does not quantify residual shape-dependent corrections.
  • domain assumption A quasi-2D trap with strong axial confinement maps to a 2D model with effective range r2D = -l2_z ln(2) (Eq. 5, Section 2).
    Taken from Refs. [21-24]; not re-derived or numerically validated for the few-body observables studied here.
  • domain assumption The correlated Gaussian basis with the stochastic variational method converges to the exact eigensolutions for the reported states (Sections 2-3).
    Standard and well-tested method, but no residual-error estimates are given; for epsilon_b > 2 hbar omega_r and N=6 convergence is explicitly not achieved (Section 3.1).
  • domain assumption The ground states considered have zero total angular momentum, so restricting to the L=0 sector captures the relevant physics (Section 3.1).
    Rotationally symmetric Hamiltonian; the experiments prepare ground states with L=0.

how reviews work

0 comments
Cite this review

Pith. "Pith review of Energetic and Structural Properties of Two-Dimensional Trapped Mesoscopic Fermi Gases." pith.science (2026). https://pith.science/paper/SN66AQIZ

@misc{pith2026250620891,
  author       = {Pith},
  title        = {Pith review of: Energetic and Structural Properties of Two-Dimensional Trapped Mesoscopic Fermi Gases},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/SN66AQIZ}},
  note         = {Machine review of arXiv:2506.20891}
}
read the original abstract

We theoretically investigate equal-mass spin-balanced two-component Fermi gases in which pairs of atoms with opposite spins interact via a short-range isotropic model potential. We probe the distinction between two-dimensional and quasi-two-dimensional harmonic confinement by tuning the effective range parameter within two-dimensional scattering theory. Our approach, which yields numerically exact energetic and structural properties, combines a correlated Gaussian basis-set expansion with the stochastic variational method. For systems containing up to six particles, we: 1) Present the ground- and excited-state energy spectra; 2) Study non-local correlations by analysing the one- and two-body density matrices, extracting from these the occupation numbers of the natural orbitals, the momentum distributions of atoms and pairs, and the molecular 'condensate fraction'; 3) Study local correlations by computing the radial and pair distribution functions. This paper extends current theoretical knowledge on the properties of trapped few-fermion systems as realised in state-of-the-art cold-atom experiments.

Figures

Figures reproduced from arXiv: 2506.20891 by the authors.

Figure 1
Figure 1. The monopole energy spectrum of (a) 1 + 1, (b) 2 + 2, and (c) 3 + 3 fer￾mions at very nearly zero effective, r2D/l 2 r = −0.001 ≈ 0. Erel is the total relative energy and ϵb is the two-body binding energy. In panels (b) and (c) the grey dashed line indicates the energy of the first state of the next (unshown) manifold. metric, only monopole excitations between states with the same (i.e., zero) total angular mo￾mentu… view at source ↗
Figure 2
Figure 2. Left panels: Ground-state occupation numbers (eigenvalues) of the one [PITH_FULL_IMAGE:figures/full_fig_p009_2.png] view at source ↗
Figure 3
Figure 3. The condensate fraction Ncond (21) as a function of the two-body binding energy ϵb for (a) 2 + 2 and (b) 3 + 3 fermions in the ground state. In both cases the effective range is very close to zero, r2D/l 2 r = −0.001 ≈ 0. 12 [PITH_FULL_IMAGE:figures/full_fig_p012_3.png] view at source ↗
Figures from the paper (6 more)
Figure 4
Figure 4. Figure 4: Left panels: The momentum distribution n↑ (k) (23) associated with the motion of spin-↑ atoms for (a) 1 + 1, (c) 2 + 2, and (e) 3 + 3 fermions in the ground state. Right panels: The momentum distribution n(K) (32) associated with the cen￾tre-of-mass motion of spin-↑-sp…
Figure 5
Figure 5. Figure 5: Left panels: The radial one-body density [PITH_FULL_IMAGE:figures/full_fig_p016_5.png]
Figure 6
Figure 6. Figure 6: The relative energy of the ground [red] and first excited state [blue] as a function of the two-body binding energy for 3 + 3 fermions in the monopole sector of zero total orbital angular momentum. Solid lines correspond to an effective range of r2D/l 2 r = −0.2 and da…
Figure 7
Figure 7. Figure 7: Occupation numbers of the one-body density matrix (a) and the reduced [PITH_FULL_IMAGE:figures/full_fig_p018_7.png]
Figure 8
Figure 8. Figure 8: The radial one-body density [panels (a), (c), (e)] and the (scaled) radial pair distribution function [panels (b), (d), (f)] for the 3 + 3 fermion ground state at three binding energies. Solid lines correspond to an effective range of r2D/l 2 r = −0.2 and dashed lines …
Figure 9
Figure 9. Figure 9: Ground-state momentum distributions for the motion of spin- [PITH_FULL_IMAGE:figures/full_fig_p020_9.png]

Discussion (0). Continue with ORCID to comment.

Reference graph

Works this paper leans on

40 extracted references · 37 canonical work pages

  1. [1]

    A. N. Wenz, G. Zürn, S. Murmann, I. Brouzos, T . Lompe and S. Jochim,From few to many: Observing the formation of a Fermi sea one atom at a time, Science 342, 457–460 (2013), doi:10.1126 /science.1240516

  2. [2]

    N. T . Zinner,Few-body physics in a many-body world, Few-Body Systems 55, 599–604 (2014), doi:10.1007 /s00601-014-0802-x

  3. [3]

    Grining, M

    T . Grining, M. Tomza, M. Lesiuk, M. Przybytek, M. Musiał, R. Moszynski, M. Lewenstein and P . Massignan,Crossover between few and many fermions in a harmonic trap, Physical Review A 92, 061601 (2015), doi:10.1103 /PhysRevA.92.061601

  4. [4]

    Rammelmüller, W

    L. Rammelmüller, W . J. Porter and J. E. Drut,Ground state of the two-dimensional attractive Fermi gas: Essential properties from few to many body, Physical Review A 93, 033639 (2016), doi:10.1103 /PhysRevA.93.033639

  5. [5]

    Levinsen, P

    J. Levinsen, P . Massignan, S. Endo and M. M. Parish,Universality of the unitary Fermi gas: A few-body perspective, Journal of Physics B: Atomic, Molecular and Optical Physics 50, 072001 (2017), doi:10.1088 /1361-6455/aa5a1e

  6. [6]

    S.-J. Ran, A. Piga, C. Peng, G. Su and M. Lewenstein, Few-body systems capture many-body physics: Tensor network approach, Physical Review B 96, 155120 (2017), doi:10.1103/PhysRevB.96.155120

  7. [7]

    Schiulaz, M

    M. Schiulaz, M. Távora and L. F . Santos,From few- to many-body quantum systems, Quantum Science and Technology 3, 044006 (2018), doi:10.1088/2058-9565/aad913. 22 SciPost Physics Core Submission

  8. [8]

    Bayha, M

    L. Bayha, M. Holten, R. Klemt, K. Subramanian, J. Bjerlin, S. M. Reimann, G. M. Bruun, P . M. Preiss and S. Jochim,Observing the emergence of a quantum phase transition shell by shell, Nature 587, 583–587 (2020), doi:10.1038 /s41586-020-2936-y

Show all 40 references
  1. [9]

    Holten, L

    M. Holten, L. Bayha, K. Subramanian, S. Brandstetter, C. Heintze, P . Lunt, P . M. Preiss and S. Jochim, Observation of Cooper pairs in a mesoscopic two-dimensional Fermi gas, Nature 606, 287–291 (2022), doi:10.1038 /s41586-022-04678-1

  2. [10]

    Serwane, G

    F . Serwane, G. Zürn, T . Lompe, T . B. Ottenstein, A. N. Wenz and S. Jochim, Deterministic preparation of a tunable few-fermion system, Science 332, 336–338 (2011), doi:10.1126 /science.1201351

  3. [11]

    E. K. Laird, B. C. Mulkerin, J. Wang and M. J. Davis, When does a Fermi puddle become a Fermi sea? Emergence of pairing in two-dimensional trapped mesoscopic Fermi gases, SciPost Physics 17, 163–200 (2024), doi:10.21468 /SciPostPhys.17.6.163

  4. [12]

    Varga and Y

    K. Varga and Y. Suzuki, Precise solution of few-body problems with the stochastic variational method on a correlated Gaussian basis, Physical Review C 52, 2885–2905 (1995), doi:10.1103 /PhysRevC.52.2885

  5. [13]

    Varga and Y

    K. Varga and Y. Suzuki, Stochastic variational method with a correlated Gaussian basis, Physical Review A 53, 1907–1910 (1996), doi:10.1103 /PhysRevA.53.1907

  6. [14]

    Suzuki and K

    Y. Suzuki and K. Varga, Stochastic Variational Approach to Quantum Mechanical Few-Body Problems, Springer Publishing, ISBN 978-3-5404-9541-3 (1998)

  7. [15]

    Mitroy , S

    J. Mitroy , S. Bubin, W . Horiuchi, Y. Suzuki, L. Adamowicz, W . Cencek, K. Szalewicz, J. Komasa, D. Blume and K. Varga, Theory and application of explicitly correlated Gaussians, Reviews of Modern Physics 85, 693–749 (2013), doi:10.1103/RevModPhys.85.693

  8. [16]

    S. F . Boys,The integral formulae for the variational solution of the molecular many-electron wave equation in terms of Gaussian functions with direct electronic correlation, Proceedings of the Royal Society of London A 258, 402–411 (1960), doi:10.1098/rspa.1960.0195

  9. [17]

    Singer, The use of Gaussian (exponential quadratic) wave functions in molecular problems — I

    K. Singer, The use of Gaussian (exponential quadratic) wave functions in molecular problems — I. General formulae for the evaluation of integrals, Proceedings of the Royal Society of London A 258, 412–420 (1960), doi:10.1098 /rspa.1960.0196

  10. [18]

    B. J. Verhaar, J. P . H. W . van den Eijnde, M. A. J. Voermans and M. M. J. Schaffrath, Scattering length and effective range in two dimensions: Application to adsorbed hydrogen atoms, Journal of Physics A: Mathematical and General 17, 595–598 (1984), doi:10.1088/0305-4470/17/3/020

  11. [19]

    S. K. Adhikari, Quantum scattering in two dimensions, American Journal of Physics 54, 362–367 (1986), doi:10.1119 /1.14623

  12. [20]

    S. K. Adhikari, W . G. Gibson and T . K. Lim,Effective-range theory in two dimensions, Journal of Chemical Physics 85, 5580–5583 (1986), doi:10.1063 /1.451572

  13. [21]

    Levinsen and M

    J. Levinsen and M. M. Parish, Bound states in a quasi-two-dimensional Fermi gas, Physical Review Letters 110, 055304 (2013), doi:10.1103 /PhysRevLett.110.055304

  14. [22]

    Kirk and M

    T . Kirk and M. M. Parish,Three-body correlations in a two-dimensional SU(3) Fermi gas, Physical Review A 96, 053614 (2017), doi:10.1103 /PhysRevA.96.053614. 23 SciPost Physics Core Submission

  15. [23]

    H. Hu, B. C. Mulkerin, U. Toniolo, L. He and X.-J. Liu, Reduced quantum anomaly in a quasi-two-dimensional Fermi superfluid: Significance of the confinement-induced effective range of interactions, Physical Review Letters 122, 070401 (2019), doi:10.1103/PhysRevLett.122.070401

  16. [24]

    X. Y. Yin, H. Hu and X.-J. Liu, Few-body perspective of a quantum anomaly in two-dimensional Fermi gases, Physical Review Letters 124, 013401 (2020), doi:10.1103/PhysRevLett.124.013401

  17. [25]

    Blume and K

    D. Blume and K. Daily ,Trapped two-component Fermi gases with up to six particles: Energetics, structural properties, and molecular condensate fraction, Comptes Rendus Physique 12, 86–109 (2011), doi:10.1016 /j.crhy .2010.11.010

  18. [26]

    von Stecher, C

    J. von Stecher, C. H. Greene and D. Blume, Energetics and structural properties of trapped two-component Fermi gases, Physical Review A 77, 043619 (2008), doi:10.1103/PhysRevA.77.043619

  19. [27]

    K. M. Daily and D. Blume, Energy spectrum of harmonically trapped two-component Fermi gases: Three- and four-particle problem, Physical Review A 81, 053615 (2010), doi:10.1103/PhysRevA.81.053615

  20. [28]

    C. J. Bradly , B. C. Mulkerin, A. M. Martin and H. M. Quiney ,Coupled-pair approach for strongly interacting trapped fermionic atoms, Physical Review A 90, 023626 (2014), doi:10.1103/PhysRevA.90.023626

  21. [29]

    X. Y. Yin and D. Blume, Trapped unitary two-component Fermi gases with up to ten particles, Physical Review A 92, 013608 (2015), doi:10.1103 /PhysRevA.92.013608

  22. [30]

    D. S. Lewart, V . R. Pandharipande and S. C. Pieper,Single-particle orbitals in liquid-helium drops, Physical Review B 37, 4950–4964 (1988), doi:10.1103/PhysRevB.37.4950

  23. [31]

    J. J. Sakurai and J. Napolitano, Modern Quantum Mechanics, Addison–Wesley Publishing, 2nd Edition, ISBN 978-0-8053-8291-4 (2010)

  24. [32]

    Levinsen and M

    J. Levinsen and M. M. Parish, Chapter 1: Strongly interacting two-dimensional Fermi gases, Annual Review of Cold Atoms and Molecules 3, 1–75 (2015), doi:10.1142/9789814667746_0001

  25. [33]

    Zwerger, ed.,Lecture Notes in Physics (vol

    W . Zwerger, ed.,Lecture Notes in Physics (vol. 836): The BCS–BEC Crossover and the Unitary Fermi Gas, Springer Publishing, ISBN 978-3-642-21977-1 (2012)

  26. [34]

    Braaten and H.-W

    E. Braaten and H.-W . Hammer,Universality in few-body systems with large scattering length, Physics Reports 428, 259–390 (2006), doi:10.1016 /j.physrep.2006.03.001

  27. [35]

    Busch, B.-G

    T . Busch, B.-G. Englert, K. Rza˙zewski and M. Wilkens, Two cold atoms in a harmonic trap, Foundations of Physics 28, 549–559 (1998), doi:10.1023 /A:1018705520999

  28. [36]

    Efimov,Weakly bound states of three resonantly interacting particles, Soviet Journal of Nuclear Physics 12, 589–601 (1971)

    V . Efimov,Weakly bound states of three resonantly interacting particles, Soviet Journal of Nuclear Physics 12, 589–601 (1971)

  29. [37]

    X.-J. Liu, H. Hu and P . D. Drummond,Exact few-body results for strongly correlated quantum gases in two dimensions, Physical Review B 82, 054524 (2010), doi:10.1103/PhysRevB.82.054524. 24 SciPost Physics Core Submission

  30. [38]

    Bjerlin, S

    J. Bjerlin, S. M. Reimann and G. M. Bruun, Few-body precursor of the Higgs mode in a Fermi gas, Physical Review Letters 116, 155302 (2016), doi:10.1103/PhysRevLett.116.155302

  31. [39]

    G. E. Astrakharchik, J. Boronat, J. Casulleras and S. Giorgini, Momentum distribution and condensate fraction of a fermion gas in the BCS–BEC crossover, Physical Review Letters 95, 230405 (2005), doi:10.1103 /PhysRevLett.95.230405

  32. [40]

    Yan and D

    Y. Yan and D. Blume, Incorporating exact two-body propagators for zero-range interactions into N-body Monte Carlo simulations, Physical Review A 91, 043607 (2015), doi:10.1103 /PhysRevA.91.043607. 25

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.