Spin Superfluidity in Biaxial Antiferromagnetic Insulators
Spin Superfluidity in Biaxial Antiferromagnetic Insulators
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DOI：
10.1103/physrevlett.118.137201
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发表时间：
2017-03-29
影响因子：
8.6
通讯作者：
Brataas, Arne
中科院分区：
文献类型：
--
作者：
Qaiumzadeh, Alireza;Skarsvag, Hans;Brataas, Arne
反铁磁体可能表现出自旋超流，因为偶极相互作用很弱。我们试图确定这种现象发生在绝缘体中，如NiO，根据之前的研究，NiO是一种很好的自旋导体。我们研究了具有弱单轴各向异性的平面反铁磁绝缘体中的非局域自旋输运。各向异性通过创建电流必须克服的实质性阈值来阻碍自旋超流。然而，我们发现，施加高磁场可以在反铁磁体的自旋翻转转变附近消除这一障碍。重要的是，自旋超流可以在许多微米范围内持续存在，即使在肮脏的样品中也是如此。
Antiferromagnets may exhibit spin superfluidity since the dipole interaction is weak. We seek to establish that this phenomenon occurs in insulators such as NiO, which is a good spin conductor according to previous studies. We investigate nonlocal spin transport in a planar antiferromagnetic insulator with a weak uniaxial anisotropy. The anisotropy hinders spin superfluidity by creating a substantial threshold that the current must overcome. Nevertheless, we show that applying a high magnetic field removes this obstacle near the spin-flop transition of the antiferromagnet. Importantly, the spin superfluidity can then persist across many micrometers, even in dirty samples.