Spin and valence-fluctuation mediated superconductivity in pressurised Fe and CeCu2(Si/Ge)2

Jaccard, D.; Holmes, A. T.

doi:10.1016/j.physb.2005.01.056

Cited by 21 publications

(21 citation statements)

References 48 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…This means that the midpoint should actually be situated at a marginally lower p VCO . Regardless of this detail, and compared to the rather qualitative lines in previous p-T phase diagrams, [23][24][25][26] the present one is the first signature of the 4f electron delocalization based on experiment. Finally, extrapolating this line, p CeCu 2 Si 2 cr (= p V ) ∼ = 4.5 ± 0.2 GPa can be deduced, so that both coordinates of the CEP are determined within the experimental errors.…”

Section: Isothermal P-dependence and 4 F Electron Delocalizationsupporting

confidence: 64%

Heavy fermion superconductor CeCu2Si2under high pressure: Multiprobing the valence crossover

Seyfarth

Rüetschi²,

Sengupta³

et al. 2012

Phys. Rev. B

View full text Add to dashboard Cite

The first heavy fermion superconductor CeCu 2 Si 2 has not revealed all its striking mysteries yet. At high pressures, superconductivity is supposed to be mediated by valence fluctuations, in contrast to ambient pressure, where spin fluctuations most likely act as pairing glue. We have carried out a multiprobe (electric transport, thermopower, ac specific heat, Hall and Nernst effects) experiment up to 7 GPa on a high-quality CeCu 2 Si 2 single crystal. For the first time, the resistivity data make it possible quantitatively to draw the valence crossover line within the p-T plane and to locate the critical end point at 4.5 ± 0.2 GPa and a slightly negative temperature. In the same pressure region, remarkable features have also been detected in the other physical properties, presumably acting as further signatures of the Ce valence crossover and the associated critical fluctuations: We observe maxima in the Hall and Nernst effects and a sign change and a strong sensitivity on magnetic field in the thermopower signal.

show abstract

Section: Isothermal P-dependence and 4 F Electron Delocalizationsupporting

confidence: 64%

Heavy fermion superconductor CeCu2Si2under high pressure: Multiprobing the valence crossover

Seyfarth

Rüetschi²,

Sengupta³

et al. 2012

Phys. Rev. B

View full text Add to dashboard Cite

show abstract

“…3͑b͒, T 1 increases with increasing pressure up to 0.9 GPa, whereas T 2 decreases. The pressure dependence of T 1 and T 2 was reported for several Ce-based Kondo compounds, such as CeCu 2 Si 2 , 28 CeCu 2 Ge 2 , 29 and CeAl 2 ͑Ref. 30͒ in which T 1 and T 2 are associated with modified Kondo temperatures owing to the CEF splitting.…”

mentioning

confidence: 83%

Pressure-induced superconductivity in the orthorhombic Kondo compoundCePtSi2

et al. 2009

View full text Add to dashboard Cite

We have discovered a member of superconductivity induced by hydrostatic pressure in an antiferromagnetic ͑AF͒ concentrated Kondo compound CePtSi 2 by measuring the resistivity and magnetoresistance. The AF transition temperature T N of 1.8 K at ambient pressure is suppressed by pressure and disappears around 1.2 GPa. Above 1.4 GPa, a superconducting phase appears between 1.4 and 2.4 GPa, with the maximum T c of 0.14 K at 1.7 GPa. The upper critical field of the superconductivity is evaluated to be 0.7 T, which is clearly larger than that of the Pauli limit predicted by the BCS theory.

show abstract

“…[31]). Moreover, the temperature dependence of resistivity shows a T 5/3 power law behavior below 30 K over the entire superconducting pressure region [30,[32][33][34][35][36]. This non-Fermi-liquid behavior (in contrast with the T 2 dependence for Fermi liquid) was attributed to ferromagnetic (FM) fluctuations according to Moriya's theory of weak itinerant magnetism [37].…”

Section: Introductionmentioning

confidence: 99%

Magnetic fluctuations and superconducting pairing in ε -iron

et al. 2020

View full text Add to dashboard Cite

We study Coulomb correlation effects and their role in superconductivity of ε-iron under pressure from 12 to 33 GPa by using a combination of density functional and dynamical mean-field theory.Our results indicate a persistence of the Fermi-liquid behavior below the temperature ∼1000 K. The Coulomb correlations are found to substantially renormalize the density of states, reducing the distance from the peak to the Fermi level to 0.4 eV compared to 0.75 eV obtained in DFT calculations. We find significant antiferromagnetic correlations, which are accompanied by the formation of short-lived local magnetic moments. We use the obtained results as a starting point for construction of the multi-band Bethe-Salpeter equation, which eigenvalues indicate that antiferromagnetic spin fluctuations may result in the superconducting pairing in ε-Fe. Moreover, the tendency to superconducting instability becomes weaker with increase of pressure, that may explain the disappearance of superconductivity at ∼30 GPa.

show abstract

Spin and valence-fluctuation mediated superconductivity in pressurised Fe and CeCu2(Si/Ge)2

Cited by 21 publications

References 48 publications

Heavy fermion superconductor CeCu2Si2under high pressure: Multiprobing the valence crossover

Heavy fermion superconductor CeCu2Si2under high pressure: Multiprobing the valence crossover

Pressure-induced superconductivity in the orthorhombic Kondo compoundCePtSi2

Magnetic fluctuations and superconducting pairing in ε -iron

Contact Info

Product

Resources

About