Université Bordeaux I, LOMA, UMR 5798, F-33400 Talence, France.
J Phys Condens Matter. 2013 Mar 27;25(12):125702. doi: 10.1088/0953-8984/25/12/125702. Epub 2013 Feb 28.
We study the anisotropy of the in-plane upper critical magnetic field coupled to the orbital motion and the spins of electrons in a layered d(x2-y2) organic superconductor in the spatially modulated Fulde-Ferrell-Larkin-Ovchinnikov phase. We show that the interplay between the nodal structure of the order parameter and its spatial modulation results in the very peculiar angular dependence of the onset of superconductivity in the high-field regime. The principal axis of the field-direction dependence of the onset of superconductivity is tilted by π/4 in the temperature range 0.056 < or approximately equal T < 0.56. In some cases the resonance between the modulation wavevector and the vector potential of a parallel magnetic field may lead to anomalous cusps in the temperature and in-plane angular dependences of the onset of superconductivity. The obtained results support the interpretation of the recent experiments as evidence of the FFLO state.
我们研究了各向异性的面内上临界磁场与轨道运动和电子的自旋在一个分层的 d(x2-y2) 有机超导体在空间调制富勒-费雷尔-拉金-奥夫钦尼科夫相。我们表明，在近藤-朗道超导理论中，有序参数的节点结构及其空间调制之间的相互作用导致了在高场区域超导起始的非常特殊的角度依赖性。在温度范围 0.056 < or approximately equal T < 0.56 内，超导起始的磁场方向依赖的主轴以π/4 的角度倾斜。在某些情况下，调制波矢和平行磁场的磁感应强度之间的共振可能导致超导起始的温度和面内角度依赖性中的异常尖峰。所得到的结果支持了最近的实验解释，作为 FFLO 状态的证据。
