AC magnetic-field response of the ferromagnetic superconductor UGe2 with different magnetized states
AC magnetic-field response of the ferromagnetic superconductor UGe2 with different magnetized states
复制标题
不同磁化状态铁磁超导体UGe2的交流磁场响应
DOI：
10.1103/physrevb.97.020509
复制
发表时间：
2018
影响因子：
3.7
通讯作者：
Yamamura Tomoo
中科院分区：
文献类型：
--
作者：
Tanaka Hiroyuki;Yamaguchi Akira;Kawasaki Ikuto;Sumiyama Akihiko;Motoyama Gaku;Yamamura Tomoo
我们对铁磁超导体在铁磁-超导相中的直流磁化强度和交流磁化率进行了平行测量。直流磁化测量表明，充分的退磁可以制备具有不同零场剩余磁化强度的各种磁化态。我们观察到这些态在大交流场幅下表现出不同的交流超导响应。退磁状态下的交流磁通穿透量较小，且有较多的磁场壁。这一结果似乎与将磁区壁视为薄弱环节的理论相矛盾。此外，铁磁磁畴壁还增强了超导的屏蔽能力。这一观察揭示了磁区壁对超导电性的作用，超导电性几十年来一直是一个有争议的问题。提出了两种可能的情况来解释磁区壁对屏蔽能力的增强。
We have performed parallel measurements of dc-magnetization and ac-magnetic susceptibility for a ferromagnetic superconductor,, in the ferromagnetic-superconducting phase. dc-magnetization measurements revealed that adequate demagnetizing of the sample allows for the preparation of various magnetized states with different zero-field residual magnetization. We observed that these states exhibit varying ac superconducting response at large ac-field amplitudes. The amount of ac flux penetration is less in the demagnetized state involving many domain walls. This result seems to contradict the theory that considers the domain walls as weak links. Moreover, the ferromagnetic domain walls enforce the shielding capability of superconductivity. This observation sheds light on the role of the domain walls on superconductivity, which has been a controversial issue for several decades. Two possible scenarios are presented to explain the enhancement of the shielding capability by the domain walls.