Pith. sign in

REVIEW 3 major objections 5 minor 45 references

Adding one winding to a coplanar magnetic ring reverses the fermion-parity assignment of neighboring flux branches.

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

2026-07-31 23:11 UTC pith:LL3TQJ5K

load-bearing objection The exact boundary-phase identity is solid and new; the parity-switch interpretation is plausible and well simulated, but rests on a low-energy factorization the paper admits is uncontrolled at U=3. the 3 major comments →

arxiv 2607.24038 v2 pith:LL3TQJ5K submitted 2026-07-27 cond-mat.str-el

Magnetic-texture winding controls fermion-parity switches in an interacting p-wave magnet ring

classification cond-mat.str-el
keywords p-wave magnetmagnetic texture windingboundary phasefermion paritytopological pairingLuther-Emery liquidflux insertionDMRG
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 establishes that the winding number M of a spin spiral on a ring enters the many-body spectrum through an exact boundary phase, not through any local band property. Because a spin-1/2 rotation through 2πM returns with sign (-1)^M, a single-valued gauge transformation converts that sign into a phase shift πM in every fixed-particle-number energy level: Spec_N H_M(φ)=Spec_N H_uni(Q_M, φ+πM), exact at any interaction strength. In the number-conserving topological phase, a global parity constraint then makes the ground-state fermion parity alternate with M and W, so adding one winding reverses the parity assignment of neighboring phase-winding branches. The author shows with number-conserving DMRG that this reversal appears as opposite flux slopes in the charging-corrected even-odd addition-energy splitting, that the leading pitch change between adjacent textures cancels under symmetric comparison, and that the finite-size splitting tracks an independently computed charge stiffness. If true, this gives a closed-geometry, particle-number-conserving probe of topological pairing that works without pairing fields or boundary Majorana modes.

Core claim

The central discovery is the exact fixed-identity Eq. (4)/(S12): for a ring with a coplanar spin texture winding M times, the full interacting spectrum at fixed particle number N equals the spectrum of the uniform rotated-frame Hamiltonian at the same pitch with boundary phase shifted by πM, level by level, for any U, J, density, and flux. The mechanism is that the local spin rotation U_j that unwinds the spiral fails to be periodic on the ring: U_{j+L}=(-1)^M U_j. Combining it with a U(1) gauge phase e^{iπMj/L} yields a single-valued transformation that maps the sign into a boundary phase. In the topological (Luther-Emery) phase, writing the occupied-band electron as a charge vertex times a

What carries the argument

The load-bearing object is the exact spectral identity Spec_N H_M(φ)=Spec_N H_uni(Q_M, φ+πM) (Eq. (4)/(S12)), derived from the spinor boundary sign h_M=(-1)^M and the single-valued combined rotation/gauge transformation V_{M,j}=e^{iπMj/L}U_j. The second ingredient is the low-energy factorization of the occupied-band electron as ψ_- ~ e^{iΘ/2}γ, together with single-valuedness fixing the neutral-fermion boundary condition η_γ=(-1)^{M+W}; in the topological phase the massive Ising spectrum then yields the parity formula P_gs(M,W)=κ(-1)^{M+W}. The first identity is exact; the second is a low-energy statement.

Load-bearing premise

The predicted parity reversal assumes that the low-energy electron in the occupied band factorizes as a charge vertex e^{iΘ/2} times a neutral Majorana fermion; if that factorization fails at the interaction strength U=3 used in the simulations, the global parity constraint and the reversal need not hold.

What would settle it

Compute the ground-state fermion parity directly at fixed particle number for adjacent windings at J=1.5, U=3, on rings L=24 and L=32: if P_gs(M,W) fails to alternate when M→M+1, or if the leading flux slopes of the signed even-odd splitting do not reverse, the parity-reversal claim is falsified even though the exact spectral identity may hold. The same measurement in the trivial phase at J=0.3 should show no reversal.

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

If this is right

  • Even and odd texture windings impose boundary phases separated by π (half the single-electron flux period) in every fixed-N sector, independently of interaction strength and many-body phase.
  • In the number-conserving topological phase, M→M+1 reverses the ground-state fermion parity of neighboring phase-winding branches, producing opposite flux slopes of the charging-corrected even-odd splitting.
  • The same boundary sign applies to any nonuniform coplanar texture with the same total winding, so the effect is a global property of winding, not of the precise texture profile.
  • Symmetric averaging of the M0−1 and M0+1 responses cancels the leading O(1/L) pitch correction, isolating the boundary-phase contribution.
  • The finite-size parity splitting equals the phase-winding energy set by the independently calculated charge stiffness, within about 1%.

Where Pith is reading between the lines

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

  • A direct experimental route would compare flux sweeps of Coulomb-blockade addition energies for two metastable adjacent windings in the same helimagnetic or synthetic ring; the predicted sign alternation of the flux slope is a sharp, model-independent signature.
  • The parity-reversal mechanism is not limited to p-wave magnets: any closed-geometry coplanar texture with integer total winding should show the same exact boundary phase, though the observable reversal additionally requires a paired neutral sector.
  • Testing the claim at stronger interactions or smaller rings, where the low-energy factorization is least controlled, would show whether the parity reversal survives; if it disappears while the exact identity remains, the factorization would be identified as the fragile step.
  • The same boundary-phase identity could be probed in cold-atom synthetic gauge platforms, where texture winding and flux insertion are engineered rather than intrinsic, making the predicted slope alternation a transport-free diagnostic.

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 / 5 minor

Summary. The manuscript studies an L-site Hubbard ring with a static coplanar magnetic spiral of integer winding M and an Aharonov–Bohm phase φ. It proves the exact fixed-particle-number spectral identity Spec_N H_M(φ) = Spec_N H_uni(Q_M, φ+πM) (Eq. (4), SM Eq. (S12)), verified level by level by exact diagonalization to 5.8×10^−14. It then uses a number-conserving charge-boson + Majorana low-energy description to derive the global parity constraint P_gs(M,W)=κ(−1)^{M+W} in the topological phase, predicting that adjacent texture windings reverse the parity assignment of phase-winding branches. DMRG simulations report alternating flux slopes of the even–odd addition-energy splitting, agreement with the independently computed charge stiffness, and finite-entanglement scaling consistent with c=3/2, interpreted as an Ising transition of the neutral sector on top of a gapless charge mode.

Significance. The exact spectral identity is a rigorous, parameter-free result with a clear and elegant message: a global boundary-condition contribution of magnetic-texture winding can appear in the interacting many-body spectrum, decoupled from the local band dispersion. The DMRG work is careful, using five- and seven-point estimators, extensive convergence checks, a symmetric pitch-cancellation protocol, and trivial-phase controls. If the parity-reversal claim is microscopically justified, the paper offers a new closed-geometry, number-conserving observable for topological pairing. The main uncertainty is not the exact identity, which is essentially airtight, but the low-energy factorization on which Eq. (6) rests and which the authors themselves flag as uncontrolled at U=3.

major comments (3)
  1. [SM S2 A; SM S3 A, Eq. (S27)] The derivation of η_γ=(−1)^{M+W} and hence of Eq. (6) assumes that the occupied-band electron factorizes as ψ_− ∼ e^{iΘ/2}γ with a well-defined pair-phase winding W. SM S2 A states that at U=3 this is “a low-energy organization rather than a parametrically controlled expansion” because virtual pair excitations into the upper hybridized band are not governed by a small ratio. This is the weakest load-bearing step for the advertised parity reversal. Please provide a direct numerical check: the ground-state occupation of the upper band, or the weight of the single-band-projected subspace, for the U=3, J=1.5 topological regime and for the trivial reference, at representative L and M. If the upper-band weight is not small, Eq. (6) is not derived for the simulated model and the parity reversal is a phenomenological low-energy interpretation rather than a consequence of the microscopic Hamilton
  2. [Eq. (6); SM S3 C] Because κ is calibrated from the measured branch assignment (SM S3 C: “the measured branch assignment calibrates κ=−1”), the DMRG alternation in Fig. 2(a) is a consistency check of Eq. (6) rather than an independent test. The paper should state this explicitly in the main text and abstract: the predictive content is the relative reversal under M→M+1, not the absolute parity sign. An independent microscopic estimate of κ, for example from the trivial-phase branch assignment or from a controlled small-system calculation, would strengthen the claim.
  3. [SM S7 B] The scope statement in SM S7 B lists two necessary conditions for Eq. (6): the ring must be longer than the neutral correlation length ξ_I, and the winding energy π²ρ_s/(2L) must lie below the lowest opposite-parity neutral excitation. The manuscript does not report ξ_I or the neutral-excitation gap for the simulated parameters. Please provide estimates of these scales, for instance from the exponential approach of the parity-splitting branches or from the Ising mass, and show that the L=16–48 data satisfy them. Without this, the topological-phase interpretation of the finite-size scaling is not fully supported.
minor comments (5)
  1. [Fig. 1(a)] The notation “periodic identification j = L ≡ 0” is confusing; use j ≡ 0 (mod L) consistently.
  2. [Abstract and Sec. 5] The phrase “support an Ising transition” is stronger than the finite-entanglement data alone, which show bond-to-bond and fit-window spread around c=3/2. Suggest “are consistent with an Ising transition” in the abstract and main text.
  3. [SM S5 C and D] Two different tables are labelled Table S6 in the Supplemental Material (Secs. S5 C and S5 D). Please renumber.
  4. [SM S5 D] The sentence “Provenance: 135 ground-state energies, all completed.” is colloquial for a formal supplement; rephrase as a descriptive statement of the data set.
  5. [SM S3 C, Eq. (S42)] The sign in Eq. (S42) depends on the calibration κ=−1. State this immediately before the equation so the reader does not mistake the sign for a universal prediction.

Circularity Check

1 steps flagged

Exact spectral identity is non-circular; only an explicit calibration of the nonuniversal sign κ is recycled into Eq. (S42), and the central M→M+1 parity reversal does not depend on that sign.

specific steps
  1. fitted input called prediction [Supplemental Material S3 C, Eq. (S42)]
    "For the present data, the measured branch assignment calibrates κ=−1 in Eq. (S30). Thus, for the even reference winding, the odd minimum is at φ=0 and the even minimum at φ=π. ... Eq. (S41) and the estimator expansion give bD(5)_{p,M0}(0)=−π²ρ_e(L)/(2L)+O(e^{−L/ξ_I})+O(L^{−3})."

    κ is fixed by the measured even/odd branch assignment, i.e. by the very ordering that bD_p(0) records; Eq. (S42) then uses κ=−1 to attach the negative sign to bD_p(0). That sign is an input, not an independent prediction. The step is non-load-bearing for the main claim: the relative reversal s_{M+1}=−s_M and the magnitude check via ρ_s do not require κ; only the absolute parity offset does.

full rationale

The central exact identity Eq. (4)/(S12) is a unitary change of frame: U_j+L=(−1)^M U_j combined with e^{iπMj/L} converts the spinor boundary sign into a U(1) phase πM, holding level-by-level in every fixed-N sector without mean-field or long-wavelength approximation; it is independently verified by exact-diagonalization residuals ~10^-14. The parity reversal Eq. (6)/(S30) follows from standard number-conserving topological-superconductor/Ising physics: ψ−∼e^{iΘ/2}γ, single-valuedness gives η_γ=(−1)^{M+W}, and the massive-Majorana spectrum gives opposite lowest parities in the topological phase. These inputs are external literature results, not self-citations by the sole author. The one mild circularity is the explicit calibration of κ=−1 from the measured branch assignment, which is then reused as the sign in Eq. (S42); because the advertised relative effect (M→M+1 reverses parity) and the ρ_s-based magnitude comparison are κ-independent, this does not compromise the derivation. The admitted lack of a parametrically controlled expansion at U=3 in SM S2 ('a low-energy organization rather than a parametrically controlled expansion') is a real limitation of the low-energy step but is not a circular reduction. Overall score 2: an essentially self-contained derivation with one minor fitted-input reuse.

Axiom & Free-Parameter Ledger

1 free parameters · 6 axioms · 0 invented entities

The paper introduces no new physical particles or forces. Its free-parameter inventory is minimal: the nonuniversal parity sign κ, explicitly calibrated from data, and the low-energy degrees of freedom (Majorana fields, phase-winding sectors) are standard Ising/bosonization constructs. The main assumptions are the frozen-texture approximation and the uncontrolled charge–neutral factorization at strong U.

free parameters (1)
  • κ = -1 (calibrated to DMRG reference-winding assignment at J=1.5)
    Nonuniversal microscopic parity sign in P_gs(M,W)=κ(−1)^(M+W). S3 C states the measured branch assignment calibrates κ=−1. The relative M→M+1 reversal is κ-independent, but the absolute zero-flux prediction Eq. (S42) depends on this calibration.
axioms (6)
  • standard math A spin-1/2 spinor rotated through 2πM returns with sign (−1)^M; classical spin vectors return identically.
    Eq. (S7): U_{M,j+L}=(−1)^M U_{M,j}. This is the root of the boundary sign h_M=(−1)^M.
  • standard math Particle-number-conserving local unitary transformations preserve the fixed-N spectrum level by level.
    Eqs. (S9)–(S12): V_{M,j}=e^{iπMj/L}U_{M,j} is single-valued and maps H_M(φ) to H_uni(Q_M, φ+πM).
  • domain assumption The magnetic texture is a static classical background with integer winding M; no spin dynamics or backaction.
    Hamiltonian Eq. (1) and S7 B explicitly state the texture is frozen; slow texture dynamics are outside the Hamiltonian.
  • domain assumption The low-energy electron in the occupied band factorizes into a charge vertex and a neutral Majorana fermion: ψ_-(x)∼e^{iΘ/2}γ.
    S3 A Eq. (S27); S2 admits this is a low-energy organization at U=3, not a parametrically controlled expansion.
  • domain assumption In the topological phase, the lowest opposite-parity state lies in an adjacent phase-winding sector, with ring longer than the neutral correlation length and π^2ρ_s/(2L) below the neutral gap.
    S3 A and S7 B state these conditions explicitly; they are necessary for the parity-reversal observable.
  • domain assumption The continuous neutral transition is governed by the decoupled Ising fixed point even in the presence of a marginal charge–Ising coupling; numerics are used to test this.
    S2 Eq. (S23) and Ref. [37]; the paper does not derive this universality from the microscopic model.

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0 comments
read the original abstract

Coplanar magnetic spirals map locally onto uniform spin--orbit-coupled wires, but on a ring the rotating spin frame can change the electronic boundary condition. We prove, level by level in every fixed-particle-number sector, that even and odd texture windings impose boundary phases separated by half the single-electron flux period. Changing the winding by one also changes the physical pitch in inverse proportion to the circumference; a symmetric comparison removes this leading pitch correction. In the number-conserving topological phase, a global parity constraint then reverses the fermion-parity assignment of neighboring phase-winding branches. Density-matrix renormalization-group simulations show this reversal, support an Ising transition coexisting with a gapless charge mode, and relate the finite-size parity splitting to an independently calculated charge stiffness. Magnetic-texture winding thus changes the many-body spectrum through a global boundary condition that is not determined by the local band dispersion, providing a closed-geometry, number-conserving probe of topological pairing.

Figures

Figures reproduced from arXiv: 2607.24038 by Hyun-Yong Lee.

Figure 1
Figure 1. Figure 1: FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p002_1.png] view at source ↗
Figure 2
Figure 2. Figure 2: FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p003_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p004_3.png] view at source ↗

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Reference graph

Works this paper leans on

45 extracted references · 1 canonical work pages · 1 internal anchor

  1. [1]

    A. Y. Kitaev, Unpaired Majorana fermions in quantum wires, Physics-Uspekhi44, 131 (2001), arXiv:cond-mat/0010440

  2. [2]

    Alicea, New directions in the pursuit of Majorana fermions in solid state systems, Rep

    J. Alicea, New directions in the pursuit of Majorana fermions in solid state systems, Rep. Prog. Phys.75, 076501 (2012), arXiv:1202.1293

  3. [3]

    R. M. Lutchyn, J. D. Sau, and S. Das Sarma, Majorana Fermions and a Topological Phase Transition in Semiconductor- Superconductor Heterostructures, Phys. Rev. Lett.105, 077001 (2010), arXiv:1002.4033

  4. [4]

    Y. Oreg, G. Refael, and F. von Oppen, Helical Liquids and Majorana Bound States in Quantum Wires, Phys. Rev. Lett. 105, 177002 (2010), arXiv:1003.1145

  5. [5]

    Mourik, K

    V. Mourik, K. Zuo, S. M. Frolov, S. R. Plissard, E. P. A. M. Bakkers, and L. P. Kouwenhoven, Signatures of Majorana Fermions in Hybrid Superconductor-Semiconductor Nanowire Devices, Science336, 1003 (2012), arXiv:1204.2792

  6. [6]

    ˇSmejkal, J

    L. ˇSmejkal, J. Sinova, and T. Jungwirth, Emerging Research Landscape of Altermagnetism, Phys. Rev. X12, 040501 (2022)

  7. [7]

    A. B. Hellenes, T. Jungwirth, R. Jaeschke-Ubiergo, A. Chakraborty, J. Sinova, and L. ˇSmejkal, P-wave magnets, arXiv preprint arXiv:2309.01607 10.48550/arXiv.2309.01607 (2023), arXiv:2309.01607 [cond-mat.mes-hall]

  8. [8]

    Brekke, P

    B. Brekke, P. Sukhachov, H. G. Giil, A. Brataas, and J. Linder, Minimal Models and Transport Properties of Unconventional 𝑝-Wave Magnets, Phys. Rev. Lett.133, 236703 (2024)

  9. [9]

    Yamada, M

    R. Yamada, M. T. Birch, P. R. Baral, S. Okumura, R. Nakano, S. Gao, M. Ezawa, T. Nomoto, J. Masell, Y. Ishihara, K. K. Kolincio, I. Belopolski, H. Sagayama, H. Nakao, K. Ohishi, T. Ohhara, R. Kiyanagi, T. Nakajima, Y. Tokura, T.-h. Arima, Y. Motome, M. M. Hirschmann, and M. Hirschberger, A metallic 𝑝-wave magnet with commensurate spin helix, Nature646, 837 (2025)

  10. [10]

    K.-M. Kim, G. Sim, and M. J. Park, Topological Ising su- perconductivity in two-dimensional𝑝-wave magnet, arXiv preprint arXiv:2605.01686 10.48550/arXiv.2605.01686 (2026), arXiv:2605.01686 [cond-mat.str-el]

  11. [11]

    Luo, Z.-T

    X.-J. Luo, Z.-T. Sun, X. Feng, M. Tian, and K. T. Law, Hidden Zeeman Field in Odd-Parity Magnets: An Ideal Platform for Topological Superconductivity, arXiv preprint arXiv:2603.15147 10.48550/arXiv.2603.15147 (2026), arXiv:2603.15147 [cond-mat.supr-con]

  12. [12]

    Nonrelativistic Spin-Orbit-Coupling Effects in Odd-Parity Coplanar Magnets

    D. Liu, Z.-Y. Zhuang, D. Zhu, Z. Wu, and Z. Yan, Nonrelativistic Spin-Orbit-Coupling Effects in Odd-Parity Coplanar Magnets, arXiv preprint arXiv:2606.23806 10.48550/arXiv.2606.23806 (2026), arXiv:2606.23806 [cond-mat.mtrl-sci]

  13. [13]

    X.-J. Yi, Y. Mao, C.-M. Miao, and Q.-F. Sun, Majorana modes in helical altermagnet without net magnetism and spin-orbit coupling, arXiv:2606.20259 (2026)

  14. [14]

    Braunecker, G

    B. Braunecker, G. I. Japaridze, J. Klinovaja, and D. Loss, Spin- selective Peierls transition in interacting one-dimensional con- ductors with spin-orbit interaction, Phys. Rev. B82, 045127 (2010), arXiv:1004.0467

  15. [15]

    Braunecker and P

    B. Braunecker and P. Simon, Interplay between Classical Magnetic Moments and Superconductivity in Quantum One- Dimensional Conductors: Toward a Self-Sustained Topolog- ical Majorana Phase, Phys. Rev. Lett.111, 147202 (2013), 6 arXiv:1307.2431

  16. [16]

    Klinovaja, P

    J. Klinovaja, P. Stano, A. Yazdani, and D. Loss, Topological Superconductivity and Majorana Fermions in RKKY Systems, Phys. Rev. Lett.111, 186805 (2013), arXiv:1307.1442

  17. [17]

    Kjærgaard, K

    M. Kjærgaard, K. W¨olms, and K. Flensberg, Majorana fermions in superconducting nanowires without spin-orbit coupling, Phys. Rev. B85, 020503 (2012)

  18. [18]

    Martin and A

    I. Martin and A. F. Morpurgo, Majorana fermions in supercon- ducting helical magnets, Phys. Rev. B85, 144505 (2012)

  19. [19]

    Fidkowski, R

    L. Fidkowski, R. M. Lutchyn, C. Nayak, and M. P. A. Fisher, Majorana zero modes in one-dimensional quantum wires with- out long-ranged superconducting order, Phys. Rev. B84, 195436 (2011), arXiv:1106.2598

  20. [20]

    J. D. Sau, B. I. Halperin, K. Flensberg, and S. Das Sarma, Num- ber conserving theory for topologically protected degeneracy in one-dimensional fermions, Phys. Rev. B84, 144509 (2011), arXiv:1106.4014

  21. [21]

    Cheng and H.-H

    M. Cheng and H.-H. Tu, Majorana edge states in interacting two-chain ladders of fermions, Phys. Rev. B84, 094503 (2011), arXiv:1106.2614

  22. [22]

    Ortiz, J

    G. Ortiz, J. Dukelsky, E. Cobanera, C. Esebbag, and C. Beenakker, Many-Body Characterization of Particle- Conserving Topological Superfluids, Phys. Rev. Lett.113, 267002 (2014), arXiv:1407.3793

  23. [23]

    Ruhman, E

    J. Ruhman, E. Berg, and E. Altman, Topological States in a One-Dimensional Fermi Gas with Attractive Interactions, Phys. Rev. Lett.114, 100401 (2015), arXiv:1412.3444

  24. [24]

    Keselman and E

    A. Keselman and E. Berg, Gapless symmetry-protected topo- logical phase of fermions in one dimension, Phys. Rev. B91, 235309 (2015)

  25. [25]

    E. M. Stoudenmire, J. Alicea, O. A. Starykh, and M. P. A. Fisher, Interaction effects in topological superconducting wires supporting Majorana fermions, Phys. Rev. B84, 014503 (2011), arXiv:1104.5493

  26. [26]

    Thomas-Markarian, K

    J. Thomas-Markarian, K. Agarwal, and I. Martin, Majorana edge modes in isolated wires, arXiv preprint arXiv:2509.00158 10.48550/arXiv.2509.00158 (2025), arXiv:2509.00158 [cond- mat.str-el]

  27. [27]

    D. Loss, P. Goldbart, and A. V. Balatsky, Berry’s phase and persistent charge and spin currents in textured mesoscopic rings, Phys. Rev. Lett.65, 1655 (1990)

  28. [28]

    Loss, Parity effects in a Luttinger liquid: Diamagnetic and paramagnetic ground states, Phys

    D. Loss, Parity effects in a Luttinger liquid: Diamagnetic and paramagnetic ground states, Phys. Rev. Lett.69, 343 (1992)

  29. [29]

    Singh Roy, M

    M. Singh Roy, M. Kumar, J. D. Sau, and S. Tewari, Fermion parity gap and exponential ground state degeneracy of the one- dimensional Fermi gas with intrinsic attractive interaction, Phys. Rev. B102, 125135 (2020)

  30. [30]

    M. F. Lapa and M. Levin, Rigorous Results on Topological Superconductivity with Particle Number Conservation, Phys. Rev. Lett.124, 257002 (2020), arXiv:1912.12307

  31. [31]

    C.-X. Liu, W. S. Cole, and J. D. Sau, Proposal for Measuring the Parity Anomaly in a Topological Superconductor Ring, Phys. Rev. Lett.122, 117001 (2019), arXiv:1803.01872

  32. [32]

    Aharonov and A

    Y. Aharonov and A. Casher, Topological Quantum Effects for Neutral Particles, Phys. Rev. Lett.53, 319 (1984)

  33. [33]

    Seidel and D.-H

    A. Seidel and D.-H. Lee, Luther–Emery liquid: Spin gap and anomalous flux period, Phys. Rev. B71, 045113 (2005)

  34. [34]

    Luther and V

    A. Luther and V. J. Emery, Backward Scattering in the One- Dimensional Electron Gas, Phys. Rev. Lett.33, 589 (1974)

  35. [35]

    Giamarchi,Quantum Physics in One Dimension, International Series of Monographs on Physics, Vol

    T. Giamarchi,Quantum Physics in One Dimension, International Series of Monographs on Physics, Vol. 121 (Oxford University Press, Oxford, 2004)

  36. [36]

    C. L. Kane, A. Stern, and B. I. Halperin, Pairing in Luttinger Liq- uids and Quantum Hall States, Phys. Rev. X7, 031009 (2017), arXiv:1701.06200

  37. [37]

    Alberton, J

    O. Alberton, J. Ruhman, E. Berg, and E. Altman, Fate of the Ising quantum critical point coupled to a gapless boson, Phys. Rev. B95, 075132 (2017), arXiv:1609.02599

  38. [38]

    Ruhman and E

    J. Ruhman and E. Altman, Topological degeneracy and pairing in a one-dimensional gas of spinless Fermions, Phys. Rev. B96, 085133 (2017)

  39. [39]

    S. R. White, Density matrix formulation for quantum renormal- ization groups, Phys. Rev. Lett.69, 2863 (1992)

  40. [40]

    Schollw ¨ock, The density-matrix renormalization group in the age of matrix product states, Ann

    U. Schollw ¨ock, The density-matrix renormalization group in the age of matrix product states, Ann. Phys. (N.Y.)326, 96 (2011), arXiv:1008.3477

  41. [41]

    Hauschild and F

    J. Hauschild and F. Pollmann, Efficient numerical simula- tions with Tensor Networks: Tensor Network Python (TeNPy), SciPost Phys. Lect. Notes , 5 (2018), code available from https://github.com/tenpy/tenpy, arXiv:1805.00055

  42. [42]

    H.-J. Kwon, K. Sengupta, and V. M. Yakovenko, Fractional ac Josephson effect in𝑝- and𝑑-wave superconductors, Eur. Phys. J. B37, 349 (2004), arXiv:cond-mat/0210148

  43. [43]

    Pollmann, S

    F. Pollmann, S. Mukerjee, A. M. Turner, and J. E. Moore, Theory of Finite-Entanglement Scaling at One-Dimensional Quantum Critical Points, Phys. Rev. Lett.102, 255701 (2009), arXiv:0812.2903

  44. [44]

    Lafarge, P

    P. Lafarge, P. Joyez, D. Esteve, C. Urbina, and M. H. Devoret, Measurement of the even-odd free-energy difference of an iso- lated superconductor, Phys. Rev. Lett.70, 994 (1993)

  45. [45]

    Magnetic-texture winding controls fermion-parity switches in an interacting𝑝-wave magnet ring

    S. M. Albrecht, A. P. Higginbotham, M. Madsen, F. Kuemmeth, T. S. Jespersen, J. Nyg˚ard, P. Krogstrup, and C. M. Marcus, Ex- ponential protection of zero modes in Majorana islands, Nature 531, 206 (2016). 7 Supplemental Material for “Magnetic-texture winding controls fermion-parity switches in an interacting𝑝-wave magnet ring” This Supplemental Material s...