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arXiv · 1806.00948

Anisotropic Superconductivity Emerging from the Orbital Degrees of Freedom in a $\Gamma_3$ Non-Kramers Doublet System

Katsunori Kubo
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Abstract

We study superconductivity in a three-orbital model for $f^2$ ions with the $\Gamma_3$ crystalline electric field (CEF) ground state. An antiferromagnetic interaction between the $\Gamma_7$ and $\Gamma_8$ orbitals is introduced to stabilize the $\Gamma_3$ CEF state. This interaction also works as an on-site attractive interaction for spin-singlet pairing between electrons in these orbitals. The interorbital pairing state composed of the $\Gamma_7$ and $\Gamma_8$ orbitals on the same site has the $E_g$ symmetry. Indeed, by applying the random phase approximation, we find that the $E_g$ spin-singlet superconducting state is realized over a wide parameter range.

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Katsunori Kubo. 2018-06-04. Anisotropic Superconductivity Emerging from the Orbital Degrees of Freedom in a $\Gamma_3$ Non-Kramers Doublet System. https://doi.org/10.7566/jpsj.87.073701

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