Quantum critical point, scaling and universality in high Tc (CaxLa1−x)(Ba2−c−xLac+x)Cu3Oy

Watkins, Byron; Chashka, H.; Direktovich, Y; Knizhnik, A.; Eckstein, Y.

doi:10.1016/j.physc.2006.06.045

Cited by 2 publications

(2 citation statements)

References 19 publications

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“…Another anomaly associated with x = 0.1 is the absence of a metallic transport at overdoping in y where T C = 0, as revealed by a minimum in the temperature dependence of (T). 51 Interpreted as absence of a quantum critical point in y, 51 this finding makes it difficult to treat formulations with x = 0.1 as a separate family of (Ca x La 1-x )(Ba 1.75-x La 0.25+x )Cu 3 O y compounds. The broadened transitions also create difficulties in quantifying a superconducting dome (T C vs y); for example, at x = 0.1 and y = 6.986, which is underdoped and above the minimum for superconductivity, the claimed T C value of about 16 K entered in the phase diagram corresponds to a specimen that is non-superconducting above 5 K and has a negative resistivity slope between 25 and 80 K (see Fig.…”

Section: B Inhomogeneous Superconductorsmentioning

confidence: 99%

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(Ba
Harshman
¹
,
Fiory
²

2012
Phys. Rev. B
10
1
34
0
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The superconductive and magnetic properties of charge-compensated (Ca x La 1−x )(Ba 1.75−x La 0.25+x )Cu 3 O y (normally denoted as CLBLCO) are considered through quantitative examination of data for electrical resistivity, magnetic susceptibility, transition width, muon-spin rotation, x-ray absorption, and crystal structure. A derivative of LaBa 2 Cu 3 O y , cation doping of this unique tetragonal cuprate is constrained by compensating La substitution for Ba with Ca substitution for La, where for 0 x 0.5 local maxima in T C occur for y near 7.15. It is shown that optimum superconductivity occurs for 0.4 x 0.5, that the superconductivity and magnetism observed are nonsymbiotic phenomena, and that charge-compensated doping leaves the carrier density in the cuprate planes nearly invariant with x, implying that only a small fraction of superconducting condensate resides therein. Applying a model of electronic interactions between physically separated charges in adjacent layers, the mean in-plane spacing between interacting charges, = 7.1206Å, and the distance between interacting layers, ζ = 2.1297Å, are determined for x = 0.45. The theoretical optimal T C0 ∝ −1 ζ −1 of 82.3 K is in excellent agreement with experiment (≈80.5 K), bringing the number of compounds for which T C 0 is accurately predicted to 37 from six different superconductor families (overall accuracy of ±1.35 K).

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Section: B Inhomogeneous Superconductorsmentioning

confidence: 99%

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(Ba
Harshman
¹
,
Fiory
²

2012
Phys. Rev. B
10
1
34
0
View full text Add to dashboard Cite

show abstract

“…Both phase diagrams suggest no QCP inside the superconducting phase. Actually, it has reported that QCP may exist at around the end point of the superconducting phase when superconductivity has completely disappeared in CLBLCO, 128 SrD-La214, 129 OD-Tl2201, 130 and OD-Bi2212. 130 The UEPD is consistent with the idea that the pseudogap phase is, if not sufficient, necessary for the high T c .…”

Section: E Comparison Between the Unified Electronic Phase Diagram An...mentioning

confidence: 99%

Unified electronic phase diagram for hole-doped high-Tccuprates

2008

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We have analyzed various characteristic temperatures and energies of hole-doped high-Tc cuprates as a function of a dimensionless hole-doping concentration (pu). Entirely based on the experimental grounds we construct a unified electronic phase diagram (UEPD), where three characteristic temperatures (T * 's) and their corresponding energies (E * 's) converge as pu increases in the underdoped regime. T * 's and E * 's merge together with the Tc curve and 3.5kBTc curve at pu ∼ 1.1 in the overdoped regime, respectively. They finally go to zero at pu ∼ 1.3. The UEPD follows an asymmetric half-dome-shaped Tc curve in which Tc appears at pu ∼ 0.4, reaches a maximum at pu ∼ 1, and rapidly goes to zero at pu ∼ 1.3. The asymmetric half-dome-shaped Tc curve is at odds with the well-known symmetric superconducting dome for La2−xSrxCuO4 (SrD-La214), in which two characteristic temperatures and energies converge as pu increases and merge together at pu ∼ 1.6, where Tc goes to zero. The UEPD clearly shows that pseudogap phase precedes and coexists with high temperature superconductivity in the underdoped and overdoped regimes, respectively. It is also clearly seen that the upper limit of high-Tc cuprate physics ends at a hole concentration that equals to 1.3 times the optimal doping concentration for almost all high-Tc cuprate materials, and 1.6 times the optimal doping concentration for the SrD-La214. Our analysis strongly suggests that pseudogap is a precursor of high-Tc superconductivity, the observed quantum critical point inside the superconducting dome may be related to the end point of UEPD, and the normal state of the underdoped and overdoped high temperature superconductors cannot be regarded as a conventional Fermi liquid phase.

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Quantum critical point, scaling and universality in high Tc (CaxLa1−x)(Ba2−c−xLac+x)Cu3Oy

Cited by 2 publications

References 19 publications

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(Ba
Harshman
¹
,
Fiory
²

2012
Phys. Rev. B
10
1
34
0
View full text Add to dashboard Cite

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(Ba
Harshman
¹
,
Fiory
²

2012
Phys. Rev. B
10
1
34
0
View full text Add to dashboard Cite

Unified electronic phase diagram for hole-doped high-Tccuprates

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Quantum critical point, scaling and universality in high Tc (CaxLa1−x)(Ba2−c−xLac+x)Cu3Oy

Cited by 2 publications

References 19 publications

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(BaHarshman1, Fiory2 2012Phys. Rev. B101340View full textAdd to dashboardCite

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(BaHarshman1, Fiory2 2012Phys. Rev. B101340View full textAdd to dashboardCite

Unified electronic phase diagram for hole-doped high-Tccuprates

Contact Info

Product

Resources

About

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(Ba
Harshman
¹
,
Fiory
²

2012
Phys. Rev. B
10
1
34
0
View full text Add to dashboard Cite

Charge compensation and optimal stoichiometry in superconducting (CaxLa1−x)(Ba
Harshman
¹
,
Fiory
²

2012
Phys. Rev. B
10
1
34
0
View full text Add to dashboard Cite