Upper critical field in superconductors near ferromagnetic quantum critical points; UCoGe

Yasuhiro Tada; Norio Kawakami; Satoshi Fujimoto

doi:10.1143/jpsjs.80sa.sa006

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arXiv · 1008.4204

Upper critical field in superconductors near ferromagnetic quantum critical points; UCoGe

Yasuhiro Tada·Norio Kawakami·Satoshi Fujimoto

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Abstract

We study the strong-coupling superconductivity near ferromagnetic quantum critical points, mainly focusing on the upper critical fields $H_{c2}$. Based on our simple model calculations, we discuss experimentally observed unusual behaviors of $H_{c2}$ in a recently discovered ferromagnetic superconductor UCoGe. Especially, the large anisotropy between $H_{c2}\parallel a$-axis and $H_{c2}\parallel c$-axis, and the strong-coupling behaviors in $H_{c2}^{\parallel a}$ are investigated. We also examine effects of non-analytic corrections in the spin susceptibility on the superconductivity, which can arise from effective long range interactions due to particle-hole excitations.

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Yasuhiro Tada, Norio Kawakami, Satoshi Fujimoto. 2010-08-25. Upper critical field in superconductors near ferromagnetic quantum critical points; UCoGe. https://doi.org/10.1143/jpsjs.80sa.sa006

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