Spin-triplet paired phases inside ferromagnet induced by Hund's rule coupling and electronic correlations: Application to ${\mathrm{UGe}}_2$

Abstract

We discuss a mechanism of real-space spin-triplet pairing, alternative to that due to quantum paramagnon excitations, and demonstrate its applicability to $\mathrm{UG}{\mathrm{e}}_2$. Both the Hund's rule ferromagnetic exchange and inter-electronic correlations contribute to the same extent to the equal-spin pairing, particularly in the regime in which the weak-coupling solution does not provide any. The theoretical results, obtained within the orbitally-degenerate Anderson lattice model, match excellently the observed phase diagram for $\mathrm{UG}{\mathrm{e}}_2$ with the coexistent ferromagnetic (FM1) and superconducting ($A_1$-type) phase. Additionally, weak $A_2$- and $A$-type paired phases appear in very narrow regions near the metamaganetic (FM2 $\to$ FM1) and FM1 $\to$ paramagnetic first-order phase-transition borders, respectively. The values of magnetic moments in the FM2 and FM1 states are also reproduced correctly in a semiquantitative manner. The Hund's metal regime is also singled out as appearing near FM1-FM2 boundary.

References in corpus (9)

• Superconductivity on the border of weak itinerant ferromagnetism in UCoGe
• Even Parity, Orbital Singlet and Spin Triplet Pairing for Superconducting $La(O_{1-x}{F}_x)FeAs$
• Unconventional Superconductivity from Local Spin Fluctuations in the Kondo Lattice
• Itinerant ferromagnetism in actinide 5f electrons system: Phenomenological analysis with spin fluctuation theory
• Ferromagnetism in UGe2 : A microscopic model
• Evidence for ferromagnetic spin-pairing superconductivity in UGe${}_2$: A ${}^{73}$Ge-NQR study under pressure
• d-wave superconductivity in the frustrated two-dimensional periodic Anderson model
• Electronic structure of UGe${}_2$ at ambient pressure: comparison with X-ray photoemission spectra
• Coexistence of spin-triplet superconductivity and ferromagnetism induced by the Hund's rule exchange

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• Interplay between band structure and Hund's correlation to increase T${}_c$ in FeSe
• Odd-Parity Spin-Triplet Superconductivity in Centrosymmetric Antiferromagnetic Metals
• Coexistent spin-triplet superconducting and ferromagnetic phases induced by the Hund's rule coupling and electronic correlations II: Effect of applied magnetic field
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• Superconducting Correlations in the One-Dimensional Kondo Lattice Models under Magnetic Fields
• Spatially modulated, orbital selective ferromagnetism in La${}_5$Co${}_2$Ge${}_3$