Fulde-Ferrell-Larkin-Ovchinnikov superconductivity in the layered organic superconductor b”-(BEDT-TTF)4[(H3O)Ga(C2O4)3]C6H5NO2
Fulde-Ferrell-Larkin-Ovchinnikov superconductivity in the layered organic superconductor b”-(BEDT-TTF)4[(H3O)Ga(C2O4)3]C6H5NO2
复制标题
层状有机超导体 b”-(BEDT-TTF)4[(H3O)Ga(C2O4)3]C6H5NO2 中的 Fulde-Ferrell-Larkin-Ovchinnikov 超导
DOI：
10.1103/physrevb.97.144505
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发表时间：
2018
期刊：
影响因子：
--
通讯作者：
P. Day
中科院分区：
文献类型：
--
作者：
S. Uji;Y. Iida;S. Sugiura;T. Isono;K. Sugii;N. Kikugawa;T. Terashima;S. Yasuzuka;H. Akutsu;Y. Nakazawa;D. Graf;P. Day
报道了层状有机超导体β“-(BEDT-TTf)4[(H3O)Ga(C2O4)3]C6H5NO2中K的电阻和磁矩测量，其中BEDT-TTf代表双(乙烯二硫)四硫富瓦烯。由于BEDT-TTF导电层之间的大阴离子，该盐的超导电性具有很强的各向异性。在平行于导电层分叉的磁场中，磁矩表现出与磁滞相关的大的抗磁信号，最高临界场T为0.4℃。在16℃以上观察到抗磁信号的大小，这表现为Fulde和Ferrell，Larkin和Ovchinnikov(FFLO)相变。由于约瑟夫森涡旋动力学的影响，层间阻力在很宽的场区内存在非零值，这源于约瑟夫森涡旋动力学。电阻二阶导数曲线在16T到16T之间连续下降，这归因于约瑟夫森涡旋晶格和FFLO相序参数振荡之间的可公度性效应。只有在近乎平行的场中才能观察到可公度效应，表明FFLO相在一个非常有限的场角范围内是稳定的。确定了温度场相图。
Resistance and magnetic torque measurements are reported in a layered organic superconductor, β”-(BEDT-TTF)4[(H3O)Ga(C2O4)3]C6H5NO2 withK, where BEDT-TTF stands for bis(ethylenedithio)tetrathiafulvalene. Because of the large anion between the BEDT-TTF conducting layers, the superconductivity of this salt is highly anisotropic. In magnetic fields parallel to the conducting layers forK, the magnetic torque shows a large diamagnetic signal associated with hysteresis up toT, suggesting the upper critical fieldT at 0.4 K. The large reduction of the diamagnetic signal is observed above 16 T, which shows a Fulde and Ferrell and Larkin and Ovchinnikov (FFLO) phase transition. ForK, the interlayer resistance has nonzero value in a wide field region up to, arising from the Josephson vortex dynamics. Successive dips in the second derivative curves of the resistance are observed between 16 T and, which are ascribed to the commensurability effect between the Josephson vortex lattice and the order parameter oscillation of the FFLO phase. The commensurability effect is observed only in nearly parallel fields, showing that the FFLO phase is stable in a very limited field angle region. The temperature-field phase diagram is determined.