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Universal optimal hole-doping concentration in single-layer high-temperature cuprate superconductors

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T. Honma, P. H. Hor

Superconductivity · Submitted 20 Feb 2006 · 36 references

Pith's reading: The authors show that the superconducting transition temperatures of single-layer cuprates collapse onto one dome when doping is expressed as a volumetric hole density, with a universal optimum near 1.6 x 10^21 cm^-3.

T0 · AI review

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arXiv IDcond-mat/0602452 (version 3)
Pith IDEUWGSSKT, Pith's permanent record of this paper and its review
CitationP. H. Hor, T. Honma. "Universal optimal hole-doping concentration in single-layer high-temperature cuprate superconductors." arXiv:cond-mat/0602452 (2006). https://pith.science/paper/EUWGSSKT
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Claim paper
The paper

The paper claims

The authors show that the superconducting transition temperatures of single-layer cuprates collapse onto one dome when doping is expressed as a volumetric hole density, with a universal optimum near 1.6 x 10^21 cm^-3.

The reading

In cuprate superconductors, scientists usually measure doping as the number of holes per copper-oxide plane, called P_pl. In single-layer materials, the optimal doping was thought to vary from about 0.16 to 0.28 holes per plane, depending on the compound. This paper proposes that these different values are an illusion of looking at a two-dimensional quantity. It defines a volumetric hole density P_3D by multiplying P_pl by the number of CuO2 planes per unit cell and dividing by the unit cell volume. When the authors plot superconducting transition temperature against this P_3D, the optimal points of four different single-layer cuprates align near 1.6 x 10^21 holes per cubic centimeter, forming one common dome. They also report that the Hall number tracks P_3D in three linear segments with slopes 1, 3.2, and 25, and that c-axis superfluid density behaves more systematically when plotted against P_3D instead of P_pl. If this rescaling is correct, it means that the material-specific optimal per-plane doping values hide a single universal volume density. However, the analysis has important caveats. Most P_pl values come from the authors' own thermoelectric-power scale, and for some samples P_pl is estimated from the very T_c data used to build the dome, which introduces circularity. The master curve is a two-parameter fit, and the Hall slopes are drawn by eye without error bars. Only four compounds are included. The result is therefore a plausible and testable phenomenological reorganization, not an independent derivation.
Extended reading notes

Core claim

The paper's central claim: 'Tc varies systematically with P3D as a superconducting dome with a universal optimal hole-doping concentration P3D^opt = 1.6 x 10^21 cm^-3 for single-layer high temperature superconductors' (Abstract). If correct, the universal 3D density, not the per-plane value, sets the optimal doping, and P3D governs 3D bulk properties such as T_c magnitude and c-axis superfluid density.

Load-bearing premise

The load-bearing premise is that the per-plane hole concentrations P_pl are correctly assigned for every material, because P_3D is a simple rescaling of P_pl. These assignments rest entirely on the Honma-Hor P_pl-scale constructed from room-temperature thermoelectric power in ref. [5], and for samples lacking thermoelectric data P_pl is back-estimated from the T_c(P_pl) curve (Section 2: 'Their Ppl are estimated from the Tc(Ppl) curve plotted in Fig. 2(a)'). If the P_pl-scale is wrong for any compound, or if the T_c-estimated P_pl biases the analysis, the claimed universal P_3D dome is an artifact of calibration.

Original abstract

We argue that in cuprate physics there are two types, hole content per CuO$_2$ plane ($P_{pl}$) and the corresponding hole content per unit volume ($P_{3D}$), of hole-doping concentrations for addressing physical properties that are two-dimensional (2D) and three-dimensional (3D) in nature, respectively. We find that superconducting transition temperature ($T_c$) varies systematically with $P_{3D}$ as a superconducting \textquotedblleft $dome$\textquotedblright with a universal optimal hole-doping concentration $P_{3D}^{opt.}$ = 1.6 $\times$ 10$^{21}$ cm$^{-3}$ for single-layer high temperature superconductors. We suggest that $P_{3D}^{opt.}$ determines the upper bound of the electronic energy of underdoped single-layer high-$T_c$ cuprates.

The compiled record

The paper's own sentences, arranged, kept beside the review and separate from it. Each label is drawn from a closed vocabulary; the number beside it is the probability the classifier gave that label. Numbers in the tables are the authors', checked by code. No sentence in this record was written by a model.

Compiled by classifier-1.13-20260917 via OpenRouter, question bank abstract-p1-20260923, 2026-09-23: 1 request, 3,270 input tokens, $0.0001 reported.

What the abstract itself states, as probabilities: claims first 0.04 · states limitation 0.10 · human participants 0.01 · controlled comparison 0.03 · randomized assignment 0.01 · states quantitative result 0.98 · compares with prior results 0.08 · mentions code or data availability 0.01.

The abstract, sentence by sentence

arXiv listing abstract v3. Results and the main claim are underlined; .

We argue that in cuprate physics there are two types, hole content per CuO$_2$ plane ($P_{pl}$) and the corresponding hole content per unit volume ($P_{3D}$), of hole-doping concentrations for addressing physical properties that are two-dimensional (2D) and three-dimensional (3D) in nature, respectively. We find that superconducting transition temperature ($T_c$) varies systematically with $P_{3D}$ as a superconducting \textquotedblleft $dome$\textquotedblright with a universal optimal hole-doping concentration $P_{3D}^{opt.}$ = 1.6 $\times$ 10$^{21}$ cm$^{-3}$ for single-layer high temperature superconductors. We suggest that $P_{3D}^{opt.}$ determines the upper bound of the electronic energy of underdoped single-layer high-$T_c$ cuprates.

background contribution method result interpretation main claim

What the classifier reports for each sentence. The number is the probability it gave the label.
#sentencerolethe authors' own workstates the main conclusionstrength
s0 We argue that in cuprate physics there are two types, hole content per CuO$_2$ plane ($P_{pl}$) and the corresponding hole content per unit volume ($P_{3D}$), of hole-doping concentrations for addressing physical properties that are two-dimensional (2D) and three-dimensional (3D) in nature, respectively. contribution 0.77 0.36 0.07 asserted 0.71
s1 We find that superconducting transition temperature ($T_c$) varies systematically with $P_{3D}$ as a superconducting \textquotedblleft $dome$\textquotedblright with a universal optimal hole-doping concentration $P_{3D}^{opt.}$ = 1.6 $\times$ 10$^{21}$ cm$^{-3}$ for single-layer high temperature superconductors. result 1.00 0.91 0.82 asserted 1.00
s2 We suggest that $P_{3D}^{opt.}$ determines the upper bound of the electronic energy of underdoped single-layer high-$T_c$ cuprates. interpretation 1.00 0.45 0.21 hedged possibility 0.98

What kind of paper the classifier reports this is: position or commentary 0.59 · evidence from analysis of existing data 0.55.

What was examined, and what was not

sources read
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not examined
  • full text
  • figures and tables
  • references and citing sentences
  • relations to other papers
levels run
  • P abstract
not run
  • S sections
  • T body sentences
  • C citations
  • R cross-paper relations

Every quoted sentence on this record is the authors'. Every label is from Pith's closed vocabulary, with the probability shown beside it. Every number in the measurements table is the authors', checked by code. Record as JSON

Figures
Figure 1. (Colour online) (a) Hall number (nH ) as a function of P3D for the single￾layer HTS. The slope of solid lines is 1 in regime-I, 3.2 in regime-II and 25 in regime-III. The data for SrD-La214 are extracted from ref. [13, 14, 15, 16]; CD-Bi2201 from ref. [8, 11, 12]; OD-Tl2201 from ref. [17, 23]. The Ppl of OD-Tl2201 by Kubo et al. [23] is estimated from the Tc(Ppl) curve. The dotted lines show P3D = 5.5×1020 cm−3 and 1.6×1021 cm−3 . (b) Same data as in graph (a) are plotted as a function of Ppl. the change in sign of RH observed in the overdoped SrD-La214 [16]. The three regimes…
Figure 2. (Colour online) (a) Superconducting transition temperature (Tc) as a function of Ppl for the single-layer HTS. The data for SrD-La214 are extracted from ref. [7, 10]. The data set for OD-Hg1201, CD-Bi2201 and OD-Tl2201 are extracted from ref. [9], [8], and [6], respectively. The solid line shows Tc curve (T max c = 37 K) reproduced by using eq. (1). (b) Same data as in graph (a) are plotted as a function of P3D. The dotted lines show P3D = 5.5 × 1020 cm−3 and 1.6 × 1021 cm−3 . The inset shows the Tc T max c vs. P3D. The solid line shows Tc T max c curve reproduced by using eq. (3).…
Figure 3. (Colour online) (a) c-axis logarismic inverse squared penetration depth (λ −2 c (0)) as a function of P3D. The data for SrD-La214 are extracted from ref. [18, 19, 21], OD-Hg1201 from ref. [21, 22] and OD-Tl2201 from ref. [20]. The dotted lines show P3D = 5.5×1020 cm−3 and 1.6×1021 cm−3 . (b) Same data as in graph (a) are plotted as a function of Ppl. The solid lines are guide for the eyes. higher than Tc calculated from eq. (3). OD-Hg1201 is the pure oxygen-doped compound, although CD-Bi2201 is the cation/oxygen co-doped compound. Accordingly, the oxygen atom within the charge…

Figures reproduced from arXiv:cond-mat/0602452 by the authors.

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Found among the papers closest to this one by title and main claim. Pith's classifier compared each pair's main results and a second model family confirmed the relation; checked against two further families, shown conflicts agreed 118 times in 120 and shown same results 218 times in 239. The quoted sentence is the other paper's main claim.

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