Pith. sign in

REVIEW 3 major objections 6 minor 37 references

The screened charge density inside a superconducting vortex core is shown to oscillate in sign with period π/k_F, at a fixed fraction of the bare bound-state ripple.

Reviewed by Pith at T0; open to challenge. T0 means a machine referee read the full paper against a public rubric. the ladder, T0–T4 →

T0 review · deepseek-v4-flash

2026-08-04 00:57 UTC pith:PKQUUQGB

load-bearing objection A genuinely new closed-form mechanism for the vortex-core 2k_F charge ripple; the main caveat is that the key mode-sum collapse rests on a normalization ansatz that is numerically checked but not physically proven. the 3 major comments →

arxiv 2608.00226 v1 pith:PKQUUQGB submitted 2026-07-31 cond-mat.supr-con math-phmath.MP

Analytical Charge Density Profile of Vortex Core in Weak-Coupling Superconductor

classification cond-mat.supr-con math-phmath.MP
keywords vortex coreCaroli–de Gennes–Matricon bound statesscreened charge densityFriedel oscillationsThomas–Fermi screeningBessel completenessBogoliubov–de Gennesweak-coupling superconductor
verification ladder T0 review T1 audit T2 compute T3 formal T4 reserved

The pith

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

This paper gives an analytic account of a long-standing numerical observation: solving Poisson's equation inside a vortex core turns a one-signed charge depletion into a charge density that alternates in sign with period π/k_F. Starting from the Caroli–de Gennes–Matricon bound states in a step-like gap, the author shows that the bound-state normalization is nearly independent of angular momentum, which lets the mode sum collapse through a Bessel completeness identity. The vortex winding removes one Bessel channel, so the density vanishes on the vortex line and carries 2k_F Friedel-like oscillations. Because the bound-state charge is not neutral, the condensate compensates it exactly at long wavelength but fails at momentum 2k_F; the surviving screened charge is a sign-alternating oscillation with amplitude reduced by the factor 4k_F²/(4k_F²+k_TF²), between one-half and three-quarters for any metal. The result explains why the oscillation is robust rather than a delicate effect.

Core claim

The central claim is Eq. (28): for 1/k_F ≪ r ≲ ξ, the full screened charge density is δn_total(r) ≈ −⟨C²⟩ [4k_F²/(4k_F²+k_TF²)] sin(2k_F r)/(π k_F r). The smooth parts of the bound-state density and its Thomas–Fermi response cancel exactly; only the 2k_F ripple survives, with an amplitude that is a fixed fraction of the bare ripple. The author derives this by replacing the mode-dependent normalization constant with its ladder average, leaving a Bessel completeness sum in which the vortex winding forbids the ν=0 channel. The paper positions this closed form as the analytical counterpart of the sign-changing screened charge found numerically in self-consistent Bogoliubov–de Gennes plus Poisson

What carries the argument

The mechanism is the Bessel-Parseval completeness identity J₀²(x)+2Σ_{ν≥1}J_ν²(x)=1, applied to the hole components of the vortex bound states. The vortex winding forces the Bessel order ν=μ+1/2 to start at 1, so the missing ν=0 term leaves 1−J₀²(k_F r): zero at the origin and oscillating at 2k_F. The near-constancy of the normalization constant C_μ (replaced by its mode average ⟨C²⟩) is what reduces the mode sum to this identity; the same structure, outside the core, gives an exponential 1/r envelope decaying on a coherence length.

Load-bearing premise

The closed form collapses only because the bound-state normalization C_μ is treated as independent of angular momentum μ and replaced by its mean ⟨C²⟩; if C_μ varied significantly across the ladder, the Bessel completeness sum would not close.

What would settle it

Compute C_μ² numerically for a smooth gap profile Δ(r)=Δ∞ tanh(r/ξ) across the CdGM ladder at k_Fξ≈64: if C_μ² deviates from its mean by more than about 10% for μ/N<0.75, the mode sum cannot collapse and the amplitude in Eq. (28) does not follow.

Watch this falsifier. Get emailed when new claim-graph text bears on it.

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If this is right

  • The screened charge inside a vortex core alternates in sign with period π/k_F, so a local probe should see sign-changing charge rather than a monotone depletion.
  • The surviving amplitude is a fixed fraction 4k_F²/(4k_F²+k_TF²) of the bare bound-state ripple, lying between one-half and three-quarters across the metallic density range; screening cannot remove or amplify it.
  • The result gives a closed-form analytic benchmark for self-consistent BdG and density-functional calculations of vortex cores in the weak-coupling limit.
  • It sharpens the statement that Thomas–Fermi screening fails in the vortex: screening works, but only with its full wavevector dependence, since the q→0 limit alone would erase the ripple.
  • The bound-state density vanishes exactly at the vortex line because the vortex winding excludes the ν=0 Bessel channel; this topological constraint is directly testable in numerical density profiles.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • Because the derivation relies only on a sharp Fermi surface, the excluded ν=0 channel, and k_F ξ ≫ 1, the same sign-alternating screened profile should appear in two-dimensional superconductors and possibly in multiband systems where each Fermi sheet contributes its own 2k_F ripple.
  • A systematic expansion in 1/N (N=k_F ξ) could replace the mode-average ⟨C²⟩ by a correction series, predicting how the amplitude drifts as the ladder top is approached and where the 6% spread in C_μ becomes visible.
  • The result suggests an STM signature: at very low temperature, maps of the screened charge or local potential near a vortex should show alternating sign with period π/k_F and amplitude scaling as (k_F ξ k_F r)^{-1}, providing a direct experimental test.

Editorial analysis

A structured set of objections, weighed in public.

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

Referee Report

3 major / 6 minor

Summary. This paper presents an analytical derivation of the spatial charge-density profile around a vortex core in a weak-coupling s-wave superconductor. The author adopts a step-like gap profile, uses the Caroli-de Gennes-Matricon/BKJT bound-state machinery, and shows that the normalization constant C_μ is nearly independent of angular momentum, which allows the partial Bessel sum for the hole density to be collapsed into the closed form 1 - J_0^2(k_F r). The screened Poisson equation is then solved by replacing ∇^2 with the appropriate wavevector for each source component. The central result, Eq. (28), is a sign-alternating 2k_F charge oscillation inside the core, with amplitude reduced by the factor 4k_F^2/(4k_F^2 + k_TF^2) relative to the bare bound-state ripple. The paper claims this is the analytical counterpart of the sign change reported numerically by Machida and Koyama.

Significance. If the central result is sound, it provides a rare closed-form benchmark for BdG+Poisson numerics in a vortex core, and it gives an elementary explanation of why Thomas-Fermi screening fails at q=2k_F: the smooth parts of the bound-state charge are neutralized, while the 2k_F ripple is only partially screened. The derivation is self-contained given standard CdGM/BKJT results, no parameter is fitted to the target sign oscillation, and the suppression factor is derived rather than tuned. The paper also contains honest numerical checks, including verification of the Poisson solver against exactly solvable cases and an explicit error analysis of the replacement trick. Those strengths are real. However, the central collapse rests on an equal-amplitude ansatz for the particle and hole components inside the core, and the paper's own footnote [27] admits that this is a choice; the numerical checks use the same ansatz, so they do not independently validate the physical input.

major comments (3)
  1. [§II.A, Eq. (8) and footnote [27]] The collapse of Eq. (16) to Eq. (18) requires the coefficient multiplying each J_{μ+1/2}^2(k_F r) to be independent of μ. Inside the step-gap core, Δ=0, the BdG equations for f_+ and f_- decouple, so the physical hole amplitude is B_μ J_{μ+1/2}(k_- r) with B_μ fixed by matching to the outer BKJT solution at r=ξ. The paper simply sets A_μ=B_μ=C_μ, and footnote [27] explicitly concedes that this is a choice, that independent amplitudes would restore continuity of f_- exactly, and that relaxing it makes C^2(μ) more strongly μ-dependent. This is not cosmetic: Eq. (2) depends only on |f_-|^2, so a mode-dependent ratio B_μ/C_μ invalidates the completeness collapse that leads to Eq. (18) and hence to the amplitude factor in Eq. (28). The numerical checks in Figs. 3 and 4 use the same common-C construction, so they validate the ansatz rather than the physical BdG eigenstates. The matching must b
  2. [§II.B, Eqs. (14)–(15) and Fig. 2] The near-constancy of C_μ^2 is presented as a 'central result' but is demonstrated only numerically, at a single value k_Fξ≈64, and for the full-spinor normalization rather than for the squared hole amplitude that actually enters Eq. (16). The paper's own WKB estimates overestimate C_μ^2 at intermediate μ (Fig. 2(a)), so the analytical support is limited. Since the final amplitude in Eq. (28) is proportional to ⟨C^2⟩, and since the collapse requires constancy of the hole-channel weights, the numerical evidence should be extended to at least one other k_Fξ (e.g., k_Fξ=10, which is used elsewhere in the paper) and should report the μ-dependence of B_μ^2 itself. Without this, the coefficient in Eq. (28) is not established.
  3. [§IV.C, Eq. (28) and Fig. 4(a)] The neutrality argument states that the smooth parts cancel and only the 2k_F ripple survives, but the paper does not check that the surviving ripple integrates to zero. Over the quoted window 1/k_F ≪ r ≲ ξ, the areal integral of sin(2k_F r)/(πk_F r) is not manifestly zero; the total charge implied by Eq. (28) is therefore, as written, not obviously consistent with exact neutrality. If higher-order corrections or outer-region (r>ξ) contributions restore global neutrality, that should be stated and shown. This is not a small point, because the electrostatic mechanism in the paper rests on the claim that the smooth compensation is complete and only the ripple remains.
minor comments (6)
  1. [Abstract and §II.A] Typo: 'deacying' should be 'decaying' in §II.A; in the abstract, '1/renvelope' should be '1/r envelope'.
  2. [Eq. (16)] The notation sum over μ from 1/2 to N-1/2 is confusing because N≡k_Fξ is not an integer. Please write the sum explicitly as over half-integers μ=1/2,3/2,…,⌊k_Fξ⌋.
  3. [Fig. 2 caption] The caption says 'N≈63.7 modes' while the text uses N≈64. Define N clearly as k_Fξ and state the mode count separately.
  4. [Eq. (20) and Fig. 4 caption] The proportionality constant in the outer solution is not specified, although normalization is central to the paper. Also, Fig. 4's caption says 'matched BKJT amplitudes outside,' which appears inconsistent with footnote [27]'s statement that the inner and outer constructions need not join continuously; please clarify what matching condition was actually imposed.
  5. [Footnote 27] Footnote 27 contains a substantive limitation: the equal-amplitude ansatz is a choice and relaxing it changes the μ-dependence of C^2(μ). Because this limitation bears directly on the central claim, it should be moved into the main text and discussed as a caveat, not confined to a footnote.
  6. [§IV.B and Supplemental Material S1] The lower-limit condition 1/k_F ≪ r for Eq. (27) is stated qualitatively; a quantitative estimate of the radius beyond which the amplitude error in Eq. (28) is below, say, 10% would be helpful for practical use of the formula.

Circularity Check

0 steps flagged

No significant circularity: the derivation is self-contained given the stated common-C ansatz; no fitted parameter is renamed as a prediction.

full rationale

The paper's central result, Eq. (28), is derived from the CdGM/BKJT bound-state machinery plus a Bessel completeness identity, not from a parameter fitted to the target sign alternation. The suppression factor 4k_F^2/(4k_F^2+k_TF^2) is obtained from the model, and the mode average <C^2> is computed from the normalization integral rather than tuned. The only load-bearing approximation is the mode-independence of C_mu (Eq. 16), which the paper supports by numerical evaluation (Fig. 2) and by the analytical estimates Eqs. (14)-(15); this is an internal consistency check, not a circular reduction. Footnote [27] openly concedes that the common amplitude in Eq. (8) is a choice and that relaxing it would make C^2(mu) more mu-dependent; this is a model limitation / correctness risk, not a circularity, because the final sign alternation is not used to define C_mu. Self-citations (Refs. [5], [30], [35]) appear only in contextual or comparative passages and are not load-bearing. The numerical verification of Eq. (28) compares the closed form with an independent finite-difference solution of the screened Poisson equation using the full mode sum, so the result is not forced by construction.

Axiom & Free-Parameter Ledger

1 free parameters · 7 axioms · 0 invented entities

The derivation relies on standard CdGM/BKJT machinery, a step-gap model, and three controlled approximations (mode-independent normalization, k_- ~ k_F, replacement trick). No new entities are introduced. The only hand-chosen input is the mode-averaged normalization, whose value is computed, not fitted.

free parameters (1)
  • mode-averaged normalization <C^2> = 9.3e-3 for Delta/E_F = 0.01, N ~ 63.7
    The amplitude of all closed-form densities. It is computed from normalization integrals, not fitted to the target oscillation, but replacing C_mu by its mean is a hand-made approximation on which the Bessel-completeness collapse depends.
axioms (7)
  • domain assumption CdGM bound-state spectrum E_mu = mu Delta^2 / E_F, with mu half-integer up to k_F xi, is taken as given.
    Section I and II: the paper explicitly takes CdGM theory as given rather than re-deriving it, so the result inherits the validity of that spectrum.
  • ad hoc to paper Step-like gap profile: Delta(r) = 0 for r < xi, Delta(r) = Delta_infty for r >= xi.
    Section I: chosen for solvability; robustness to smooth gap profiles is asserted in Section V but not derived.
  • ad hoc to paper Normalization constant C_mu is nearly independent of mu and is replaced by its mean <C^2>.
    Section II.B: verified numerically within 6% for mu/N < 0.75 at N ~ 64, but not proven; the closed-form mode sum depends on this.
  • domain assumption k_- ~ k_F, i.e. dropping q = k_F E/(2 E_F) to leading order in Delta/E_F.
    Section II.A: valid for weak coupling and central to applying the Bessel completeness identity with a single wavevector.
  • standard math Bessel completeness identity J_0^2 + 2 sum_{nu>=1} J_nu^2 = 1, applied after extending the finite ladder sum to infinity.
    Eq. (17), NIST DLMF; extension justified by exponential smallness of J_nu(x) for nu >> x.
  • domain assumption Thomas-Fermi screening with a static local k_TF and the screened Poisson equation.
    Section IV: follows Ref. [19]; ignores full q-dependence of the dielectric function except at 2k_F.
  • domain assumption Replacement trick: nabla^2 -> -q^2 for oscillating and smooth source terms.
    Section IV.B and Supplemental Sec. S1: approximate but validated against an exactly solvable disc and with error analysis.

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Cite this review

Pith. "Pith review of Analytical Charge Density Profile of Vortex Core in Weak-Coupling Superconductor." pith.science (2026). https://pith.science/paper/PKQUUQGB

@misc{pith2026260800226,
  author       = {Pith},
  title        = {Pith review of: Analytical Charge Density Profile of Vortex Core in Weak-Coupling Superconductor},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/PKQUUQGB}},
  note         = {Machine review of arXiv:2608.00226}
}
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read the original abstract

Self-consistent Bogoliubov-de Gennes calculations have long shown that solving the Poisson equation inside a superconducting vortex turns a one-signed charge depletion into a modulation that alternates in sign with period $\pi/k_F$. We give an elementary account of that result. Taking the Caroli-de Gennes-Matricon bound states in a step-like gap, we show that the normalization of the bound-state spinor is nearly independent of angular momentum, which collapses the mode sum into closed form. Inside the core the vortex winding removes one Bessel channel from a completeness sum, so the density vanishes on the vortex line and carries Friedel-like oscillations of wavevector $2k_F$; outside it the sum gives a $1/r$ envelope decaying over a coherence length, with a residual ripple. The bound-state charge does not integrate to zero, so neutrality obliges the extended states to compensate it exactly. That compensation is complete at long wavelength but fails at the diameter of the Fermi circle, and what survives is a sign-alternating $2k_F$ modulation reduced only by $4k_F^2/(4k_F^2+k_{TF}^2)$, a factor lying between one-half and three-quarters for any metal. The oscillation is therefore not a delicate effect but a consequence of neutrality and the inefficiency of screening at large momentum transfer: in the screened total the smooth terms cancel and only the ripple is left.

Figures

Figures reproduced from arXiv: 2608.00226 by Chi-Ken Lu.

Figure 1
Figure 1. Figure 1: FIG. 1. CdGM bound-state wavefunctions computed with [PITH_FULL_IMAGE:figures/full_fig_p004_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2. Normalization constant [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3. Charge-density perturbation [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4. Screening of the CdGM charge, computed with [PITH_FULL_IMAGE:figures/full_fig_p008_4.png] view at source ↗

discussion (0)

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Reference graph

Works this paper leans on

37 extracted references

  1. [1]

    Caroli, P.G

    C. Caroli, P.G. De Gennes, and J. Matricon. Bound fermion states on a vortex line in a type ii supercon- ductor.Physics Letters, 9(4):307–309, 1964

  2. [2]

    M. T. Deng, Carlos Pay´ a, Pablo San-Jose, Elsa Prada, C. M. Marcus, and S. Vaitiek˙ enas. Caroli–de Gennes– Matricon analogs in full-shell hybrid nanowires.Phys. Rev. Lett., 134:206302, May 2025

  3. [3]

    Topological super- conductors: a review.Reports on Progress in Physics, 80(7):076501, may 2017

    Masatoshi Sato and Yoichi Ando. Topological super- conductors: a review.Reports on Progress in Physics, 80(7):076501, may 2017

  4. [4]

    N. B. Kopnin and M. M. Salomaa. Mutual friction in superfluid 3He: Effects of bound states in the vortex core. Phys. Rev. B, 44:9667–9677, Nov 1991

  5. [5]

    Zero-energy vortex bound states in noncentrosymmetric superconductors.Phys

    Chi-Ken Lu and Sungkit Yip. Zero-energy vortex bound states in noncentrosymmetric superconductors.Phys. Rev. B, 78:132502, Oct 2008

  6. [6]

    Topological order and non-abelian statistics in noncentrosymmetrics-wave superconduc- tors.Phys

    Satoshi Fujimoto. Topological order and non-abelian statistics in noncentrosymmetrics-wave superconduc- tors.Phys. Rev. B, 77:220501(R), Jun 2008

  7. [7]

    Schnyder, Shinsei Ryu, Akira Furusaki, and Andreas W

    Andreas P. Schnyder, Shinsei Ryu, Akira Furusaki, and Andreas W. W. Ludwig. Classification of topological in- sulators and superconductors in three spatial dimensions. Phys. Rev. B, 78:195125, Nov 2008

  8. [8]

    Band-resolved Caroli–de Gennes– Matricon states of multiple-flux-quanta vortices in a multiband superconductor.Science Advances, 9(36):eadh9163, 2023

    Thomas Gozlinski, Qili Li, Rolf Heid, Ryohei Nemoto, Roland Willa, Toyo Kazu Yamada, J¨ org Schmalian, and Wulf Wulfhekel. Band-resolved Caroli–de Gennes– Matricon states of multiple-flux-quanta vortices in a multiband superconductor.Science Advances, 9(36):eadh9163, 2023

  9. [9]

    Discrete en- ergy levels of Caroli-de Gennes-Matricon states in quan- tum limit in fete0.55se0.45.Nature Communications, 9(1):970, 2018

    Mingyang Chen, Xiaoyu Chen, Huan Yang, Zengyi Du, Xiyu Zhu, Enyu Wang, and Hai-Hu Wen. Discrete en- ergy levels of Caroli-de Gennes-Matricon states in quan- tum limit in fete0.55se0.45.Nature Communications, 9(1):970, 2018

  10. [10]

    Vortex-core spectroscopy of d-wave cuprate high- temperature superconductors.Physica C: Superconduc- tivity and its Applications, 615:1354386, 2023

    Ivan Maggio-Aprile, Tejas Parasram Singar, Christophe Berthod, Tim Gazdi´ c, Jens Bru´ er, and Christoph Ren- ner. Vortex-core spectroscopy of d-wave cuprate high- temperature superconductors.Physica C: Superconduc- tivity and its Applications, 615:1354386, 2023

  11. [11]

    Vortices in high- temperature superconductors.Rev

    Gianni Blatter, Mikhail Feigel’man, Vadim Geshkenbein, Anatoli Larkin, and Valerii Vinokur. Vortices in high- temperature superconductors.Rev. Mod. Phys., 66:1125– 1388, 1994

  12. [12]

    Vortex dynamics and the Hall anomaly: A microscopic analysis.Phys

    Anne van Otterlo, Mikhail Feigel’man, Vadim Geshken- bein, and Gianni Blatter. Vortex dynamics and the Hall anomaly: A microscopic analysis.Phys. Rev. Lett., 75:3736–3739, Nov 1995

  13. [13]

    N. B. Kopnin. Vortex dynamics and mutual friction in superconductors and Fermi superfluids.Rep. Prog. Phys., 65(11):1633, 2002

  14. [14]

    Springer, 1999

    Carl M Bender and Steven A Orszag.Advanced mathe- matical methods for scientists and engineers: Asymptotic methods and perturbation theory. Springer, 1999

  15. [15]

    K¨ ummel, A

    John Bardeen, R. K¨ ummel, A. E. Jacobs, and L. Tewordt. Structure of vortex lines in pure supercon- ductors.Phys. Rev., 187:556–569, Nov 1969

  16. [16]

    Van der Marel

    D. Van der Marel. Anomalous behaviour of the chem- ical potential in superconductors with a low density of 10 charge carriers.Physica C: Superconductivity, 165(1):35– 43, 1990

  17. [17]

    Khomskii and Feodor V

    Daniil I. Khomskii and Feodor V. Kusmartsev. Charge redistribution and properties of high-temperature super- conductors.Phys. Rev. B, 46:14245–14248, Dec 1992

  18. [18]

    D. I. Khomskii and A. Freimuth. Charged vortices in high temperature superconductors.Phys. Rev. Lett., 75:1384– 1386, Aug 1995

  19. [19]

    Electrostatics of vortices in Type-II superconductors.Phys

    Gianni Blatter, Mikhail Feigel’man, Vadim Geshkenbein, Anatoli Larkin, and Anne van Otterlo. Electrostatics of vortices in Type-II superconductors.Phys. Rev. Lett., 77:566–569, Jul 1996

  20. [20]

    Relation between vortex core charge and vortex bound states.Journal of the Physical Society of Japan, 67(10):3368–3371, 1998

    Nobuhiko Hayashi, Masanori Ichioka, and Kazushige Machida. Relation between vortex core charge and vortex bound states.Journal of the Physical Society of Japan, 67(10):3368–3371, 1998

  21. [21]

    Machida and T

    M. Machida and T. Koyama. Friedel oscillation in charge profile and position dependent screening around a super- conducting vortex core.Phys. Rev. Lett., 90:077003, Feb 2003

  22. [22]

    Friedel oscillations of vortex bound states under extreme quantum limit in KCa 2Fe4As4F2.Phys

    Xiaoyu Chen, Wen Duan, Xinwei Fan, Wenshan Hong, Kailun Chen, Huan Yang, Shiliang Li, Huiqian Luo, and Hai-Hu Wen. Friedel oscillations of vortex bound states under extreme quantum limit in KCa 2Fe4As4F2.Phys. Rev. Lett., 126:257002, Jun 2021

  23. [23]

    Detecting Friedel oscilla- tions in ultracold Fermi gases.The European Physical Journal D, 71(9):232, 2017

    Keno Riechers, Klaus Hueck, Niclas Luick, Thomas Lompe, and Henning Moritz. Detecting Friedel oscilla- tions in ultracold Fermi gases.The European Physical Journal D, 71(9):232, 2017

  24. [24]

    AM Gabovich, LG Il’Chenko, EA Pashitski ˇ ı, and Yu A Romanov. Screening of charges and Friedel oscillations of the electron density in metals having differently shaped fermi surfaces.Soviet Journal of Experimental and The- oretical Physics, 48(124), 1978

  25. [25]

    Ribeiro, Donghyung Lee, Attila Cangi, Peter Elliott, and Kieron Burke

    Raphael F. Ribeiro, Donghyung Lee, Attila Cangi, Peter Elliott, and Kieron Burke. Corrections to Thomas-Fermi densities at turning points and beyond.Phys. Rev. Lett., 114:050401, Feb 2015

  26. [26]

    See Supplemental Material for the validity of the replace- ment used to solve the screened Poisson equation, the verification of the numerical solver against exactly solv- able cases, and an error analysis of the replacement

  27. [27]

    The replacement is not optional. The slow-mode coordi- natex(r) is imaginary forr < rt, so the slow-mode ansatz is undefined throughout the classically forbidden region, which occupies a fractionµ/Nof the core radius—one half on average over the ladder, and 0.99 for the highest mode. That region is not negligible: it supplies 2–11% ofI in for typical mode...

  28. [28]

    The exception is the immediate neighbourhood ofr t, where the two BKJT components visibly separate: the hole component dips before turning up while the elec- tron component rises monotonically. The mixing an- gle is pinned toη(r t) = 0 becauseY µ(kρr) is the ex- ponentially growing solution inside the turning point, so any admixture would destroy regulari...

  29. [29]

    Release 1.2.4 of 2025-03-15; F

    NIST digital library of mathematical functions.https: //dlmf.nist.gov/. Release 1.2.4 of 2025-03-15; F. W. J. Olver, A. B. Olde Daalhuis, D. W. Lozier, B. I. Schneider, R. F. Boisvert, C. W. Clark, B. R. Miller, B. V. Saunders, H. S. Cohl, and M. A. McClain, eds

  30. [30]

    Chi-Ken Lu and Igor F. Herbut. Zero modes and charged Skyrmions in graphene bilayer.Phys. Rev. Lett., 108:266402, Jun 2012

  31. [31]

    Ashcroft and N.D

    N.W. Ashcroft and N.D. Mermin.Solid State Physics. HR W international editions. Holt, Rinehart and Win- ston, 1976

  32. [32]

    Alexander L. Fetter. Spherical impurity in an infinite su- perconductor.Phys. Rev., 140:A1921–A1936, Dec 1965

  33. [33]

    Cambridge University Press, 1958

    Michael J Lighthill.An introduction to Fourier analysis and generalised functions. Cambridge University Press, 1958

  34. [34]

    Polarizability of a two-dimensional electron gas.Phys

    Frank Stern. Polarizability of a two-dimensional electron gas.Phys. Rev. Lett., 18:546–548, Apr 1967

  35. [35]

    Friedel oscillation near a van Hove sin- gularity in two-dimensional Dirac materials.Journal of Physics: Condensed Matter, 28(6):065001, jan 2016

    Chi-Ken Lu. Friedel oscillation near a van Hove sin- gularity in two-dimensional Dirac materials.Journal of Physics: Condensed Matter, 28(6):065001, jan 2016

  36. [36]

    L. N. Oliveira, E. K. U. Gross, and W. Kohn. Density- functional theory for superconductors.Phys. Rev. Lett., 60:2430–2433, Jun 1988

  37. [37]

    Self-consistent elec- tronic structure of a vortex line in a type-II superconduc- tor.Phys

    Fran ¸ cois Gygi and Michael Schl¨ uter. Self-consistent elec- tronic structure of a vortex line in a type-II superconduc- tor.Phys. Rev. B, 43:7609–7621, Apr 1991. 11 Supplemental Material S1. V ALIDITY OF THE REPLACEMENT TRICK IN SOL VING SCREENED POISSON EQUA TION The screened Poisson equation of the main text, ∇2 −k 2 TF ϕ=− 4πe ε δnbound,(S1) is line...