Triplet pairing mechanisms from Hund's-Kondo models: applications to UTe$_{2}$ and CeRh$_{2}$As$_{2}$

Tamaghna Hazra; Piers Coleman

doi:10.1103/physrevlett.130.136002

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arXiv · 2205.13529

Triplet pairing mechanisms from Hund's-Kondo models: applications to UTe$_{2}$ and CeRh$_{2}$As$_{2}$

Tamaghna Hazra·Piers Coleman

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Abstract

Observing that several U and Ce based candidate triplet superconductors share a common structural motif, with pairs of magnetic atoms separated by an inversion center, we hypothesize a triplet pairing mechanism based on an interplay of Hund's and Kondo interactions that is unique to this structure. In the presence of Hund's interactions, valence fluctuations generate a triplet superexchange between electrons and local moments. The offset from the center of symmetry allows spin-triplet pairs formed by the resulting Kondo effect to delocalize onto the Fermi surface, precipitating superconductivity. We demonstrate this mechanism within a minimal two-channel Kondo lattice model and present support for this pairing mechanism from existing experiments.

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Tamaghna Hazra, Piers Coleman. 2022-05-26. Triplet pairing mechanisms from Hund's-Kondo models: applications to UTe$_{2}$ and CeRh$_{2}$As$_{2}$. https://doi.org/10.1103/physrevlett.130.136002

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