New Fe-based superconductors: properties relevant for applications
M Putti, I Pallecchi, E Bellingeri, M Tropeano, C Ferdeghini, A Palenzona C Tarantini, A Yamamoto, J Jiang, J Jaroszynski, F Kametani, D Abraimov, A Polyanskii,… 展开作者
M Putti, I Pallecchi, E Bellingeri, M Tropeano, C Ferdeghini, A Palenzona C Tarantini, A Yamamoto, J Jiang, J Jaroszynski, F Kametani, D Abraimov, A Polyanskii, J D Weiss, E E Hellstrom, A Gurevich, D C Larbalestier, R Jin, B C Sales, A S Sefat, M A McGuire, D Mandrus, P Cheng, Y Jia, H H Wen, S Lee, C B Eom
Less than two years after the discovery of high temperature superconductivity in oxypnictide LaFeAs(O,F) several families of superconductors based on Fe layers (1111, 122, 11, 111) are available. They share several characteristics with cuprate superconductors that compromise easy applications, such as the layered structure, the small coherence length, and unconventional pairing, On the other hand the Fe-based superconductors have metallic parent compounds, and their electronic anisotropy is generally smaller and does not strongly depend on the level of doping, the supposed order parameter symmetry is s wave, thus in principle not so detrimental to current transmission across grain boundaries. From the application point of view, the main efforts are still devoted to investigate the superconducting properties, to distinguish intrinsic from extrinsic behaviours and to compare the different families in order to identify which one is the fittest for the quest for better and more practical superconductors. The 1111 family shows the highest Tc, huge but also the most anisotropic upper critical field and in-field, fan-shaped resistive transitions reminiscent of those of cuprates, while the 122 family is much less anisotropic with sharper resistive transitions as in low temperature superconductors, but with about half the Tc of the 1111 compounds. An overview of the main superconducting properties relevant to applications will be presented. Upper critical field, electronic anisotropy parameter, intragranular and intergranular critical current density will be discussed and compared, where possible, across the Fe-based superconductor families.
Some kinetic properties of the two-band superconductors
在M.E.的评论中，Palistrant（arXiv：cond-mat/0305496）阐述了能带重叠的超导体理论的主要结果。该评论提供了一个该理论的作者V.A.Moskalenko教授及其同事的经典论文的参考文献列表。该理论已由M. E. Palistrant教授及其同事推广到载流子密度降低的情况。评论中还包括了相应的参考资料。我们认为，除了上述评论之外，提供涵盖我们对具有重叠能带的超导体的动力学性质的研究的参考文献将是有用的。特别提到了多年前获得的一些重要结果：掺杂双带超导体的Ginsburg-Landau（GL）方程和杂质对能隙的影响，以及有关双带超导体动力学性质的结果。
Self-consistent interface properties of d and s-wave superconductors
本文发展了一种自洽求解超导体Bogoliubov de Gennes方程的递推方法。该方法允许的配对相互作用是本地或非本地对应的s和d波超导，分别。利用这种方法，我们研究了各种S-N和S-S界面的性质。特别地，我们计算了以下几何结构的空间变化的态密度和序参量：（i）s波超导体到正常金属，（ii）d波超导体到正常金属，（iii）d波超导体到s波超导体。我们发现，在界面处的态密度有一个复杂的结构，包括正常的表面Friedel振荡的影响，空间变化的间隙和间隙内的Andeev状态，和微妙的影响与间隙和正常的van Hove峰的相互作用的状态密度。在体d波超导体的情况下，表面导致不同的序参量对称性的界面附近的混合和大量的局部填充的间隙。
Structural, Magnetic and Electronic Properties of the Iron-Chalcogenide A$_x$Fe$_{2-y}$Se$_2$ (A=K, Cs, Rb, Tl and etc.) Superconductors
本文报道了一种新的铁硫系超导体A $_x$ Fe $_{2-y}$ Se $_2$（A=K，Cs，Rb，Tl等）的发现。铁基超导体具有许多独特的性质，如母体化合物可能的绝缘状态、铁空位的存在及其有序性、一种新的磁结构及其与超导电性的相互作用，以及不同于其它铁基超导体的特殊电子结构等，引起了人们的广泛关注。本文对这种新型超导体的结构、磁性和电子学性质作了简要的评述，重点讨论了它的电子结构和超导能隙。在论文的最后讨论了问题和未来前景。
Nature of the quantum insulator to superconductor and superconductor to normal state transitions in cuprate superconductors
本文用量子临界现象的标度理论详细分析了La $_{2-x}$ Sr $_{x}$ CuO $_{4}$，Y $_{0.8}$ Ca $_{0.2}$-123，Tl-1212和Tl-2201的各种超导性质。我们的结果包括：实验数据是完全符合的2D绝缘体到超导体（ISQ）的过渡在欠掺杂的限制。量子临界性质似乎是相当于那些肮脏的2D玻色子系统与长程库仑相互作用。与以前的证据一起，这种转变似乎是铜酸盐超导体的一般特征。3D超导体到正常态的量子跃迁（SNQ）被证明不那么独特。需要更多的实验数据来明确地解决这种转变的性质。
Microscopic properties of fractional vortices and domain walls in three-band $s+is$ superconductors
Department of Physics, The Royal Institute of Technology（皇家理工学院物理系）；Wallenberg Initiative Materials Science for Sustainability, Department of Physics, The Royal Institute of Technology（瓦伦堡可持续发展材料科学倡议，皇家理工学院物理系）
Physical properties of the noncentrosymmetric superconductor Mg_10Ir_19B_16
比热，电阻率和磁化率的高品质样品的Mg 10 Ir 19 B16的测量提供了一个自洽的确定其超导性能。结果表明，Mg_（10）Ir_（19）B_（16）是一种Ⅱ型超导体（Tc=4.45K，k（0）=20），电子-声子耦合常数l_ep=0.66。的T-依赖的比热的分析表明，超导性能是由一个s-波间隙（D=0.7毫电子伏）。点接触隧穿数据提供了多个超导间隙的证据，从强不对称的自旋轨道耦合预期。
