High-harmonic generation in graphene enhanced by elliptically polarized light excitation
High-harmonic generation in graphene enhanced by elliptically polarized light excitation
复制标题
DOI：
10.1126/science.aam8861
复制
发表时间：
2017-05-19
期刊：
影响因子：
56.9
通讯作者：
Tanaka, Koichiro
中科院分区：
文献类型：
--
作者：
Yoshikawa, Naotaka;Tamaya, Tomohiro;Tanaka, Koichiro
石墨烯的电子性质可以引起一系列非线性光学响应。高次谐波产生是一种非常理想的非线性光学过程，它起源于强光场诱导的相干电子运动。在这里，我们报告在室温下中红外激光脉冲激发的石墨烯中观察到的九阶谐波。石墨烯中的HHG通过椭圆偏振激光激发而增强，并且所产生的谐波辐射具有特定的偏振。通过对固体中的HHG进行完全量子力学处理，可以重现观察到的椭圆率依赖性。石墨烯的零能隙性质导致了HHG的独特性质，我们的发现为研究无质量狄拉克费米子的强场和超快动力学以及非线性行为开辟了可能性。
The electronic properties of graphene can give rise to a range of nonlinear optical responses. One of the most desirable nonlinear optical processes is high-harmonic generation (HHG) originating from coherent electron motion induced by an intense light field. Here, we report on the observation of up to ninth-order harmonics in graphene excited by mid-infrared laser pulses at room temperature. The HHG in graphene is enhanced by an elliptically polarized laser excitation, and the resultant harmonic radiation has a particular polarization. The observed ellipticity dependence is reproduced by a fully quantum mechanical treatment of HHG in solids. The zero-gap nature causes the unique properties of HHG in graphene, and our findings open up the possibility of investigating strong-field and ultrafast dynamics and nonlinear behavior of massless Dirac fermions.