论文标题
两光子顶点在狄拉克材料的非线性响应中的主要作用
Dominant Role of Two-Photon Vertex in Nonlinear Response of Dirac Materials
论文作者
论文摘要
使用保存的Baym-Kadanoff方法，我们提出了在存在无序散射的情况下，狄拉克系统对电场的非线性直流响应的完全令人信服的理论。我们表明，非线性术语是由占主导地位的两光子顶点的出现明显统治的，该顶点在裸露的层面和有限型偶联极限也没有。这种两光子顶点的自我生成突出了散射速率在非线性状态下频率和场依赖性的关键作用。我们的研究揭示了狄拉克材料的非线性响应中一种新型的多体机制，其效果被认为是可观察到的。
Using a conserving Baym-Kadanoff approach, we present a fully compelling theory of nonlinear dc response of a Dirac system to electric fields in the presence of disorder scattering. We show that the nonlinear terms are strikingly ruled by the appearance of a dominant two-photon vertex which is absent at the bare level and finite even in the weak-coupling limit. Such two-photon vertex self-generation highlights the crucial role of the frequency and field dependence of the scattering rates in the nonlinear regime. Our study reveals a novel many-body mechanism in the nonlinear response of Dirac materials whose effects are predicted to be observable.
