Dynamics of Self-Induced Quantum Vortices in Ferromagnetic Superconductor RuSr2YCU2O8

从Ru-和Cu的MKR研究中，我们已经提出了在铜超导体RuSr_2YCu_2O_H （RuY1212）中超导性和铁磁性共存的证据。在零场处观察到Ru-NMR信号在射频场中有较大的增强，表明在居里温度T_M = 150 K以下的有序RuO_2平面上存在铁磁成分。在超导起始温度Tc（起始温度）= 45 K以下，有序RuO_2平面和CuO_2平面内的核自旋-晶格弛豫速率1/T_I显著降低，表明在微观尺度上RuO_2平面内超导间隙与FM分量共存。此外，在Tc(0) ~ 23 K，电阻率变为零时，观察到^<10>(L/T_I)处有一个尖峰峰，我们认为是由FM分量波动引起的自生涡旋运动诱发了RuY1212在Tc（起始）和Tc（零）之间的电阻率。我们还报道了T_c=108 K的五层化合物HgBa_2Ca_4Cu_5O_y （h2 -1245）的超导性和反铁磁性共存，该化合物由两种CuO_2平面组成，即三个内平面（IP）和两个外平面（OP）。Cu-NMR研究研究表明optimally-doped OP经历supercondcting (SC)过渡T_c = 108 K,而三underdoped IP的做一个反铁磁性的(AF)过渡低于T_x ~ 60 K的铜的时刻~ 0.3 - -0.4μ_ < K ^ + > AF自旋极化的IP被发现在SC诱发内部同一标准的相机会观察到金属行为的IP给SC和AF有序参数共存的可能性在一个CuO_2平面。

Frora Ru- and Cu MKR studies, we have presented evidence for coexistence of superconductivity and ferroraagnetism in a cuprate superconductor RuSr_2YCu_2O_H (RuY1212). The observation of a large enhancement of a radio-frequency field for the Ru-NMR signal at zero field reveals the existence of a ferromagnetic (FM) component in the ordered RuO_2 plane below a Curie temperature of T_M = 150 K. Just best below the onset temperature of superconductivity Tc(onset)= 45 K, a remarkable decrease of the nuclear spin-lattice relaxation rate 1/T_I was observed within the ordered RuO_2 plane as well as the CuO_2 plane revealing that the superconducting gap coexists with the FM component in the RuO_2 plane on a microscopic scale. In addition, from the the observation of a sharp pesk in ^<10>(L/T_I) at Tc(zero) 〜23 K where the resistivity becomes zero, we suggest that the motion of self-induced vortices originating from fluctuations of the FM component induces the resistivity between T c(onset) and T c(zero) in RuY1212.We alos have reported a coexistence of superconductivity and antiferromagnetism in five-layered compound HgBa_2Ca_4Cu_5O_y (Hg-1245) with T_c=108 K, which is composed of two types of CuO_2 planes in a unit cell, Three inner planes (IP) and twe outer planes (OP). The Cu-NMR study study has revealed that the optimally-doped OP undergoes a supercondcting (SC) transition at T_c=108 K, whereas the three underdoped IP's do an antiferromagnetic (AF) transition below T_x〜60 K with the Cu moments of 〜0.3-0.4μ_<K^+> The AF spin polarization at the IP is found to induce an internal fied at the SC OP. The observed metallic behavior at the IP gives the possibility that SC and AF order parameter coexist in a single CuO_2 plane.