Source capture
Authors Yinghao Zhu, Di Peng, Enkang Zhang, Bingying Pan, Xu Chen, Zhenfang Xing, Cuiying Pei, Feiyu Li, Yanpeng Qi, Junjie Zhang, Qiaoshi Zeng, Jian-gang Guo, Jun Zhao
arXiv / Publisher https://arxiv.org/abs/2603.01062
PDF https://arxiv.org/pdf/2603.01062
Relevance score 4.240
Primary category cond-mat.supr-con
Published 2026-03-03
Research paradigm Theoretical
Sample form Single Crystal

Summary

This response paper clarifies the evaluation method of the superconducting shielding volume fraction in pressurized Ruddlesden-Popper nickelates. The authors point out that their method directly follows the standard magnetostatic self-consistency relation for finite samples (Equations 2–4), where the measured susceptibility is corrected by the demagnetization factor N to obtain the intrinsic susceptibility, from which the shielding volume fraction is estimated as f ≈ −χ. This method has been widely adopted in the superconductor literature for decades. Taking single-crystal sample S6 as an example, the self-consistent formula yields a superconducting shielding volume fraction of approximately 86% at 50 GPa and 5 K, and about 82% at 40 GPa. The authors argue that the fundamental flaw in the critique presented in arXiv:2602.19282 lies in the assumption by the opposing party that the measured diamagnetic moment is linearly proportional to the superconducting shielding volume fraction, and their simple normalization via calculating the full-shielding Meissner moment. This assumption is invalid for thin disk-shaped samples with strong demagnetization, because the internal field and magnetization are self-consistently coupled through the demagnetizing field, resulting in a nonlinear relationship between the measured moment and the shielding fraction, and consequently yielding an underestimated value of about 60% by the opposing method. The paper also discusses the applicability of the single-demagnetization-factor framework, noting that the sample has a uniform structure and high quality, supporting this macroscopic description, while the artificially constructed phase-separation model by the opposing party is not applicable here. The authors conclude that the method based on magnetostatic self-consistency is correct and a widely adopted standard approach.

Materials

Methods

Keywords

Highlights

  • The assumption that the measured diamagnetic moment is linearly proportional to the superconducting shielding volume fraction is not valid for strongly demagnetized, thin disk-like specimens.
  • The single-N framework is applicable for high-quality single crystals but not for phase-separated models with explicit inhomogeneities.
  • The method based on magnetostatic self-consistency (Eqs. 2–4) is widely adopted in the superconductivity literature for decades.

Conclusions

  • The estimation of the superconducting shielding volume fraction in pressurized Ruddlesden–Popper nickelates is conducted within the well-established magnetostatic self-consistency framework, as outlined in Eqs. (2)–(4).
  • This framework ensures that the demagnetization-corrected superconducting shielding volume fractions are consistent with long-standing experimental practices in the superconductivity community.
  • The discrepancies claimed in Ref. [1] arise from a fundamental flaw in their methodology, particularly the assumption that the measured diamagnetic moment is linearly proportional to the superconducting shielding volume fraction in the presence of a finite demagnetization factor N.
  • Therefore, our approach, grounded in magnetostatic self-consistency, remains the correct and widely accepted method for estimating superconducting shielding volume fractions.

Main claims

  • The demagnetization-corrected superconducting shielding volume fraction follows the standard magnetostatic self-consistency relation, widely used in the literature for decades.
    • Evidence: abstract states method follows from standard self-consistency and has been widely adopted,full_text provides detailed derivation and references 6-35
  • The critique in arXiv:2602.19282 is flawed because it assumes linear proportionality between measured moment and shielding fraction, which is invalid for strongly demagnetized samples.
    • Evidence: abstract: 'the discrepancies claimed in Ref. [1] stem from a fundamental flaw in their approach',full_text: 'the central flaw is that this normalization implicitly assumes linear scaling'
  • For sample S6 at 50 GPa, the self-consistent method yields a superconducting shielding volume fraction of ≈86%, while the alternative method underestimates it to ≈60%.
    • Evidence: full_text provides explicit calculation: χ0 = -2.405, χ = -0.863, f ≈ 86%,summary_en states ≈86% at 50 GPa and ≈82% at 40 GPa

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