Spin-Triplet Superconductivity in UTe2 and Ferromagnetic Superconductors

Abstract

The spin-triplet state is most likely realized in uranium ferromagnetic superconductors, UGe2, URhGe, UCoGe. The microscopic coexistence of ferromagnetism and superconductivity means that the Cooper pair should be realized under the strong internal field due the ferromagnetism, leading to the spin-triplet state with equal spin pairing. The field-reinforced superconductivity, which is observed in all three materials when the ferromagnetic fluctuations are enhanced, is one of the strong evidences for the spin-triplet superconductivity. We present here the results of a newly discovered spin-triplet superconductor, UTe2, and compare those with the results of ferromagnetic superconductors. Although no magnetic order is found in UTe2, there are similarities between UTe2 and ferromagnetic superconductors. For example, the huge upper critical field exceeding the Pauli limit and the field-reentrant superconductivity for H || b-axis are observed in UTe2, URhGe and UCoGe. We also show the specific heat results on UTe2 in different quality samples, focusing on the residual density of states in the superconducting phase.

arXiv comment6 pages, 3 figures, accepted for publication in JPSJ Conference Proceedings

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Cited by in corpus (10)

• Unconventional Superconductivity in UTe2
• Multiple Superconducting Phases and Unusual Enhancement of the Upper Critical Field in UTe2
• Orientation of point nodes and nonunitary triplet pairing tuned by the easy-axis magnetization in UTe2
• Magnetic Properties under Pressure in Novel Spin-Triplet Superconductor UTe2
• Inhomogeneous Superconducting State Probed by ${}^{125}$Te NMR on UTe$_2
• Pressure-induced structural phase transition and new superconducting phase in UTe2
• Spin triplet superconductivity driven by finite momentum spin fluctuations
• c axis electrical transport at the metamagnetic transition in the heavy-fermion superconductor UTe2 under pressure
• Anisotropic field-induced changes in the superconducting order parameter of UTe2
• Low temperature specific heat and thermal conductivity in superconducting UTe2