Possible Fulde-Ferrell-Larkin-Ovchinnikov inhomogeneous superconducting state in CeCoIn5

Pramana

P G Pagliuso²  J L Sarrao¹  R Movshovich1¹  C Capan¹  A Bianchi³ 

[1] Los Alamos National Laboratory, Los Alamos, New Mexico 87545, USA$$;Instituto de Física `Gleb Wathagin', UNICAMP, 13083-970, Campinas, Brazil$$;Hochfeldlabor Dresden Forschungszentrum Rossendorf Postfach 51 01 19 01314, Dresden, Germany$$

关键词: Inhomogeneous superconductivity;    heavy fermion;    Fulde-Ferrell;    Larkin-Ovchinnikov.;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We present specific heat and thermal conductivity of the heavy fermion superconductor CeCoIn5 in the vicinity of the superconducting critical field 𝐻c2, measured with magnetic field in the plane of this quasi-2D compound and at temperatures down to 50 mK. The superconducting phase diagram and the first order nature of the superconducting phase transition at high fields close to a critical field 𝐻c2 indicate the importance of the Pauli limiting effect in CeCoIn5. In the same range of magnetic field we observe a second specific heat anomaly within the superconducting state, and interpret it as a signature of a Fulde-Ferrell-Larkin-Ovchinnikov (FFLO) inhomogeneous superconducting state. In addition, the thermal conductivity data as a function of field display a kink at a field 𝐻k below the superconducting critical field, which closely coincides with the low temperature anomaly in specific heat tentatively identified with the appearance of the FFLO superconducting state. The enhancement of thermal conductivity within the FFLO state calls for further theoretical investigations of the real space structure of the order parameter (and in particular, the structure of vortices) and of the thermal transport within the inhomogeneous FFLO state.

【 授权许可】

Unknown