We study the generation of harmonics from graphene under the influence of an artificial magnetic field, generated via bending of a graphene flake. We show how the Landau level structure induced by the pseudomagnetic field breaks the centrosymmetry of graphene, thus allowing the generation of even harmonics. We also show that depending on the impinging pulse duration, the nonlinear signal does not only contain the integer harmonics of the impinging pulse but also its half-integer ones due to the peculiar square-root-like nature of Landau levels in graphene.

中文翻译：

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在应变石墨烯中产生半整数谐波和有效的太赫兹到可见光频率转换

我们研究了在人造磁场的影响下石墨烯的谐波产生，通过石墨烯薄片的弯曲产生。我们展示了由伪磁场引起的朗道能级结构如何打破石墨烯的中心对称性，从而产生偶次谐波。我们还表明，根据撞击脉冲持续时间，非线性信号不仅包含撞击脉冲的整数谐波，而且由于石墨烯中朗道能级的特殊平方根性质，还包含其半整数谐波。