论文标题
辐照石墨烯中的非平衡rkky相互作用
Non-Equilibrium RKKY Interaction in Irradiated Graphene
论文作者
论文摘要
我们证明，即使在弱驱动器机构中，也可以通过时间周期性的驾驶场来对石墨烯中的Ruderman-Kittel-Kasuya-Yosida（Rkky）相互作用进行强烈修改。这种效果是由于当石墨烯暴露于圆形极化光线时，在狄拉克点开设了动力带隙。使用Keldysh-Floquet Green的功能，我们开发了一个理论框架来计算弱周期性驱动器下时间平均的Rkky耦合，并表明它在未脱落的石墨烯中的幅度可以通过提高驱动强度来减少，同时大多要保持其铁磁或抗磁力磁性特征。在掺杂的石墨烯中，我们发现带有驾驶场可调节的时期的Rkky振荡。当打开足够强大的驱动器，使费米水平完全在动态打开的间隙中，rkky耦合的行为从掺杂到未掺杂的辐照的石墨烯的质量变化。
We demonstrate that the Ruderman-Kittel-Kasuya-Yosida (RKKY) interaction in graphene can be strongly modified by a time-periodic driving field even in the weak drive regime. This effect is due to the opening of a dynamical band gap at the Dirac points when graphene is exposed to circularly polarized light. Using Keldysh-Floquet Green's functions, we develop a theoretical framework to calculate the time-averaged RKKY coupling under weak periodic drives and show that its magnitude in undoped graphene can be decreased controllably by increasing the driving strength, while mostly maintaining its ferromagnetic or antiferromagnetic character. In doped graphene, we find RKKY oscillations with a period that is tunable by the driving field. When a sufficiently strong drive is turned on that brings the Fermi level completely within the dynamically opened gap, the behavior of the RKKY coupling changes qualitatively from that of doped to undoped irradiated graphene.
