论文标题
光引起的异常大厅电导率在大规模3D DIRAC SEMIMETAL CO $ _3 $ sn $ _2 $ s $ _2 $
Light-induced anomalous Hall conductivity in massive 3D Dirac semimetal Co$_3$Sn$_2$S$_2$
论文作者
论文摘要
当时间反转或空间反向对称性损坏时，Weyl半法可能会从Dirac半学出来。最近，基于浮雕理论提出的，即使圆形极化光（CPL）也可以将狄拉克半法被转换为Weyl Semimetals。在这里，我们通过使用超级额外的中型中型泵 - terahertz faraday proproscopoy测量了巨大的3D DIRAC半际性CO $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ _2 $ sn $ _2 $ s $ _2 $，使用超级额外的中型泵 - terahertz faraday proproscopoy使用超级磁性阶段，在大型3D DIRAC半含量co $ _2 $ _2 $ _2 $中测量CPL诱导的异常霍尔电导率（AHC），从而调查了这种狄拉克 - 韦尔的转换的可能性。我们发现，观察到的AHC的野外强度和驱动频率依赖性是由CPL诱导的非零浆果曲率很好地解释的，该曲率与Floquet理论预测的DIRAC谱带相关。 DIRAC带的估计分裂达到了大约60％的质量间隙，并且计算出的CPL诱导的AHC定量地重现了实验观察结果，这表明了从大型Dirac semimetals实现Floquet-Weyl状态的有希望的途径。
Weyl semimetals can emerge from Dirac semimetals when the time-reversal or spatial-inversion symmetries are broken. Recently, it has been proposed based on the Floquet theory that Dirac semimetals can be converted into Weyl semimetals even by shining circularly polarized light (CPL). Here we have investigated the possibility of such a Dirac-Weyl conversion by measuring the CPL-induced anomalous Hall conductivity (AHC) in a massive 3D Dirac semimetal Co$_3$Sn$_2$S$_2$ in the paramagnetic phase using ultrafast mid-infrared pump-terahertz Faraday rotation probe spectroscopy. We find that the field-strength and driving frequency dependence of the observed AHC is well accounted for by CPL-induced nonzero Berry curvature associated with the splitting of the Dirac bands as predicted by the Floquet theory. The estimated splitting of the Dirac bands reaches about 60 % of the mass gap and the calculated CPL-induced AHC quantitatively reproduces the experimental observation, demonstrating a promising route toward the realization of Floquet-Weyl states from massive Dirac semimetals.
