论文标题
用局部传导带对非磁性半导体的超快磁化理论
Theory of ultrafast magnetization of non-magnetic semiconductors with localized conduction bands
论文作者
论文摘要
飞秒光脉冲对非磁性半导体的磁化对于实现材料中自旋动力学的全光控制和开发更快的记忆设备至关重要。但是，其检测条件在很大程度上未知。在这项工作中，我们确定了观察超快磁化的标准，并严格地讨论了阻碍其实验检测的困难。我们表明，可以在具有非常局部的传导带态和更脱位的价带的化合物中观察到非磁性半导体的超快速磁化，例如在P-D电荷转移缝隙的情况下。通过使用受约束和时间依赖的密度函数理论模拟，我们证明了可以通过逼真的脉冲在逼真的脉冲中诱导瞬时磁磁性的瞬态铁磁状态。铁磁状态在钒（传导）和氧（Valence）状态上具有相反的磁矩。我们的方法可以超越V2O5的情况，因为它确定了非磁性半导体中超快磁性筛选的关键要求。
The magnetization of a non-magnetic semiconductor by femtosecond light pulses is crucial to achieve an all-optical control of the spin dynamics in materials and to develop faster memory devices. However, the conditions for its detection are largely unknown. In this work we identify the criteria for the observation of ultrafast magnetization and critically discuss the difficulties hindering its experimental detection. We show that ultrafast magnetization of a non magnetic semiconductor can be observed in compounds with very localized conduction band states and more delocalized valence bands, such as in the case of a p-d charge transfer gap. By using constrained and time dependent density functional theory simulations, we demonstrate that a transient ferrimagnetic state can be induced in diamagnetic semiconductor V2O5 via ultrafast pulses at realistic fluences. The ferrimagnetic state has opposite magnetic moments on vanadium (conduction) and oxygen (valence) states. Our methodology outruns the case of V2O5 as it identifies the key requirements for a computational screening of ultrafast magnetism in non-magnetic semiconductors.
