Lebrun R, Ross A, Gomonay O, Baltz V, Ebels U, Barra A-L, Qaiumzadeh A, Brataas A, Sinova J, Kläui M
Unité Mixte de Physique, CNRS, Thales, Université Paris-Saclay, 91767, Palaiseau, France.
Institut für Physik, Johannes Gutenberg-Universität Mainz, 55099, Mainz, Germany.
Nat Commun. 2020 Dec 10;11(1):6332. doi: 10.1038/s41467-020-20155-7.
Antiferromagnetic materials can host spin-waves with polarizations ranging from circular to linear depending on their magnetic anisotropies. Until now, only easy-axis anisotropy antiferromagnets with circularly polarized spin-waves were reported to carry spin-information over long distances of micrometers. In this article, we report long-distance spin-transport in the easy-plane canted antiferromagnetic phase of hematite and at room temperature, where the linearly polarized magnons are not intuitively expected to carry spin. We demonstrate that the spin-transport signal decreases continuously through the easy-axis to easy-plane Morin transition, and persists in the easy-plane phase through current induced pairs of linearly polarized magnons with dephasing lengths in the micrometer range. We explain the long transport distance as a result of the low magnetic damping, which we measure to be ≤ 10 as in the best ferromagnets. All of this together demonstrates that long-distance transport can be achieved across a range of anisotropies and temperatures, up to room temperature, highlighting the promising potential of this insulating antiferromagnet for magnon-based devices.
反铁磁材料可以承载自旋波，其极化方向根据磁各向异性从圆极化到线极化变化。到目前为止，据报道只有具有圆极化自旋波的易轴各向异性反铁磁体能在微米级的长距离上携带自旋信息。在本文中，我们报道了在赤铁矿的易平面倾斜反铁磁相以及室温下的长距离自旋输运，在这种情况下，线性极化的磁振子直观上并不被认为能携带自旋。我们证明，自旋输运信号在通过易轴到易平面的莫林转变时持续下降，并在易平面相中通过电流诱导的成对线性极化磁振子持续存在，其退相长度在微米范围内。我们将长输运距离解释为低磁阻尼的结果，我们测得其与最佳铁磁体一样≤10。所有这些共同表明，长距离输运可以在一系列各向异性和温度范围内实现，直至室温，突出了这种绝缘反铁磁体在基于磁振子的器件方面的广阔潜力。
