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Fulde-Ferrell-Larkin-Ovchinnikov Superconducting State in CeCoIn5

A. Bianchi·R. Movshovich·C. Capan·A. Lacerda·P. G. Pagliuso·J. L. Sarrao
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Abstract

We report specific heat measurements of the heavy fermion superconductor CeCoIn5 in the vicinity of the superconducting critical field H_{c2}, with magnetic field in the [110], [100], and [001] directions, and at temperatures down to 50 mK. The superconducting phase transition changes from second to first order for field above 10 T for H || [110] and H || [100]. In the same range of magnetic field we observe a second specific heat anomaly within the superconducting state. We interpret this anomaly as a signature of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) inhomogeneous superconducting state. We obtain similar results for H || [001], with FFLO state occupying a smaller part of the phase diagram.

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A. Bianchi, R. Movshovich, C. Capan, A. Lacerda, P. G. Pagliuso, J. L. Sarrao. 2003-04-18. Fulde-Ferrell-Larkin-Ovchinnikov Superconducting State in CeCoIn5. https://doi.org/10.1103/physrevlett.91.187004

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