Calorimetric evidence for a Fulde-Ferrell-Larkin-Ovchinnikov superconducting state in the layered organic superconductor κ-(BEDT-TTF)2Cu(NCS)2
Calorimetric evidence for a Fulde-Ferrell-Larkin-Ovchinnikov superconducting state in the layered organic superconductor κ-(BEDT-TTF)2Cu(NCS)2
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DOI：
10.1103/physrevlett.99.187002
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发表时间：
2007-11-02
影响因子：
8.6
通讯作者：
Wosnitza, J.
中科院分区：
文献类型：
--
作者：
Lortz, R.;Wang, Y.;Wosnitza, J.
本文研究了层状有机超导体kappa-（BEDT-TTF）（2）Cu（NCS）（2）（BEDT-TTF为双乙撑二硫代四硫富瓦烯）在垂直和平行于超导层外加磁场下的比热。在21 T以上的平行场中，超导转变变为一阶，这表明达到了保利极限场。而不是饱和在这个字段值，上临界场急剧增加，第二个一阶过渡线出现在超导相。我们的结果给出了强有力的证据，相，从正常状态的均匀超导状态是一个实现的Fulde-Ferrell-Larkin-Ovchinnikov状态。
The specific heat of the layered organic superconductor kappa-(BEDT-TTF)(2)Cu(NCS)(2), where BEDT-TTF is bisethylenedithio-tetrathiafulvalene, has been studied in magnetic fields up to 28 T applied perpendicular and parallel to the superconducting layers. In parallel fields above 21 T, the superconducting transition becomes first order, which signals that the Pauli-limiting field is reached. Instead of saturating at this field value, the upper-critical-field increases sharply and a second first-order transition line appears within the superconducting phase. Our results give strong evidence that the phase, which separates the homogeneous superconducting state from the normal state is a realization of a Fulde-Ferrell-Larkin-Ovchinnikov state.