Ultrafast magnetic dynamics in insulating YBa2Cu3O6.1 revealed by time resolved two-magnon Raman scattering
Ultrafast magnetic dynamics in insulating YBa2Cu3O6.1 revealed by time resolved two-magnon Raman scattering
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DOI：
10.1038/s41467-020-16275-9
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发表时间：
2020-05-21
影响因子：
16.6
通讯作者：
Reznik, Dmitry
中科院分区：
文献类型：
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作者：
Yang, Jhih-An;Pellatz, Nicholas;Reznik, Dmitry
在真实的时间内测量和控制磁序和相关性是与磁存储和自旋电子学相关的快速发展的科学领域。在这些实验中，超短激光脉冲（泵浦）首先被带有电偶极矩的激发吸收。然后，它们将能量提供给由时间分辨探针监测的磁性子系统。铁磁体的研究已经取得了很大的进展，但反铁磁体的研究更具挑战性。在这里，我们介绍了时间分辨的两个磁振子拉曼散射作为一个真实的时间探针的磁相关性，特别是非常适合于反铁磁体。它的应用程序的反铁磁电荷转移绝缘体YBa_2Cu_3O_6.1显示快速退磁90 fs内的光激发。弛豫回到热平衡的特征在于慢得多的时间尺度。我们解释这些结果的电荷部门的缓慢松弛和快速平衡的磁部门的prethermal状态，其特征在于由参数变化缓慢的电荷部门放松。许多实验技术的局限性使得很难获得材料中磁相互作用的清晰图像，留下了许多重要的问题。Yang等人证明，时间分辨双磁振子拉曼散射可以探测反铁磁YBa 2 Cu 3 O 6. 1的动力学。
Measurement and control of magnetic order and correlations in real time is a rapidly developing scientific area relevant for magnetic memory and spintronics. In these experiments an ultrashort laser pulse (pump) is first absorbed by excitations carrying electric dipole moment. These then give their energy to the magnetic subsystem monitored by a time-resolved probe. A lot of progress has been made in investigations of ferromagnets but antiferromagnets are more challenging. Here, we introduce time-resolved two-magnon Raman scattering as a real time probe of magnetic correlations especially well-suited for antiferromagnets. Its application to the antiferromagnetic charge transfer insulator YBa2Cu3O6.1 revealed rapid demagnetization within 90fs of photoexcitation. The relaxation back to thermal equilibrium is characterized by much slower timescales. We interpret these results in terms of slow relaxation of the charge sector and rapid equilibration of the magnetic sector to a prethermal state characterized by parameters that change slowly as the charge sector relaxes. The limitations of many experimental techniques make it difficult to obtain a clear picture of magnetic interactions in materials, leaving many important questions open. Yang et al. demonstrate that time-resolved two-magnon Raman scattering can probe the dynamics of antiferromagnetic YBa2Cu3O6.1.