论文标题
二阶非线性在2D六角纳米结构中的微观量子描述以外
Microscopic quantum description of second-order nonlinearities in 2D hexagonal nanostructures beyond the Dirac cone approximation
论文作者
论文摘要
六边形二维纳米结构（例如石墨烯，硅和德国烯）具有较大的载体费米速度，因此具有较大的载体速度，因此，较大的轻度耦合强度使这些材料具有纳米式电动电动机的有希望的元素。尽管这些材料是氯粒对称的，但空间分散剂却非常大，因此此类材料的二阶非线性响应与非核对称2D的二阶非线性响应相当。无质量的迪拉克费米子的二阶响应已经进行了广泛的研究，但是到目前为止，在整个布里鲁因区域中都缺乏一般的方法。为了完成这一差距，在当前的论文中，我们开发了一个通用的量子力学理论，该理论是对狄拉克锥近似之外的平面二阶非线性响应，并且适用于六角形紧密结合纳米结构的整个布里鲁因区域。我们介绍了适用于任意三波混合过程的2D六角纳米结构的非线性敏感性张量的明确计算。
Single layers of hexagonal two-dimensional nanostructures such as graphene, silicene, and germanene exhibit large carrier Fermi velocities and, consequently, large light-matter coupling strength making these materials promising elements for nano-opto-electronics. Although these materials are centrosymmetric, the spatial dispersion turns out to be quite large allowing the second-order nonlinear response of such materials to be comparable to the non-centrosymmetric 2D ones. The second-order response of massless Dirac fermions has been extensively studied, however a general approach correct over the full Brillouin zone is lacking so far. To complete this gap, in the current paper we develop a general quantum-mechanical theory of the in-plane second-order nonlinear response beyond the Dirac cone approximation and applicable to the full Brillouin zone of the hexagonal tight-binding nanostructures. We present explicit calculation of the nonlinear susceptibility tensor of 2D hexagonal nanostructures applicable to arbitrary three-wave mixing processes.
