High-field state of the flux-line lattice in the unconventional superconductor CeCoIn5
High-field state of the flux-line lattice in the unconventional superconductor CeCoIn5
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DOI：
10.1103/physrevb.70.020506
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发表时间：
2003-12
影响因子：
3.7
通讯作者：
Tadataka Watanabe;Y. Kasahara;K. Izawa;T. Sakakibara;Y. Matsuda;C. J. Beek;T. Hanaguri;H. Shishido;R. Settai;Y. Ōnuki
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文献类型：
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作者：
Tadataka Watanabe;Y. Kasahara;K. Izawa;T. Sakakibara;Y. Matsuda;C. J. Beek;T. Hanaguri;H. Shishido;R. Settai;Y. Ōnuki
超声波速度测量的非常规超导体CeCoIn_5具有极大的泡利顺磁磁化率揭示了一个不寻常的结构转变的磁通线晶格（FLL）附近的上临界场。的过渡字段相吻合的热容测量揭示了第二阶相变。在过渡的声速降低是一致的崩溃的FLL倾斜模量和交叉准二维FLL钉扎。这些结果提供了强有力的证据，高场状态是Fulde-Ferrel-Larkin-Ovchinikov相，其中序参数是空间调制的，并具有垂直于涡旋排列的平面节点。
Ultrasound velocity measurements of the unconventional superconductor CeCoIn_5 with extremely large Pauli paramagnetic susceptibility reveal an unusual structural transformation of the flux line lattice (FLL) in the vicinity of the upper critical field. The transition field coincides with that at which heat capacity measurements reveal a second order phase transition. The lowering of the sound velocity at the transition is consistent with the collapse of the FLL tilt modulus and a crossover to quasi two-dimensional FLL pinning. These results provide a strong evidence that the high field state is the Fulde-Ferrel-Larkin-Ovchinikov phase, in which the order parameter is spatially modulated and has planar nodes aligned perpendicular to the vortices.