Laser-induced ultrafast spin reorientation in the antiferromagnet TmFeO3
Laser-induced ultrafast spin reorientation in the antiferromagnet TmFeO3
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DOI：
10.1038/nature02659
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发表时间：
2004-06-24
期刊：
影响因子：
64.8
通讯作者：
Rasing, T
中科院分区：
文献类型：
--
作者：
Kimel, AV;Kirilyuk, A;Rasing, T
所有磁性有序材料可以分为两大类：铁磁体（1，2）和反铁磁体（3）。自古以来，铁磁材料就有着广泛的应用领域（4），从指南针到计算机存储，最近又到磁性随机存取存储器和自旋电子学（5）。相反，反铁磁（AFM）材料，虽然代表了绝大多数的磁有序材料，在很长一段时间内，只有学术兴趣。这两种磁性材料之间的根本区别表现在它们对外部磁场的反应上--在反铁磁体中，交换相互作用导致净磁化为零。相关的净角动量的缺乏应该会导致原子力显微镜自旋动力学速度加快几个数量级（6，7）。在这里，我们表明，使用短激光脉冲，反铁磁体TmFeO 3的自旋确实可以在几皮秒的时间尺度上被操纵，而铁磁体的时间尺度为数百皮秒（8-12）。由于反铁磁体中自旋的超快动力学是交换偏置器件的关键问题，因此这一发现可以扩展AFM材料目前有限的应用范围。
All magnetically ordered materials can be divided into two primary classes: ferromagnets(1,2) and antiferromagnets(3). Since ancient times, ferromagnetic materials have found vast application areas(4), from the compass to computer storage and more recently to magnetic random access memory and spintronics(5). In contrast, antiferromagnetic (AFM) materials, though representing the overwhelming majority of magnetically ordered materials, for a long time were of academic interest only. The fundamental difference between the two types of magnetic materials manifests itself in their reaction to an external magnetic field-in an antiferromagnet, the exchange interaction leads to zero net magnetization. The related absence of a net angular momentum should result in orders of magnitude faster AFM spin dynamics(6,7). Here we show that, using a short laser pulse, the spins of the antiferromagnet TmFeO3 can indeed be manipulated on a timescale of a few picoseconds, in contrast to the hundreds of picoseconds in a ferromagnet(8-12). Because the ultrafast dynamics of spins in antiferromagnets is a key issue for exchange-biased devices(13), this finding can expand the now limited set of applications for AFM materials.