Even-order high-harmonic generation from solids in velocity gauge  

作　　者：Jiayuan Cao Na Li Ya Bai Peng Liu Ruxin Li 曹佳媛;李娜;白亚;刘鹏;李儒新(State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China)

机构地区：[1]State Key Laboratory of High Field Laser Physics and CAS Center for Excellence in Ultra-Intense Laser Science,Shanghai Institute of Optics and Fine Mechanics,Chinese Academy of Sciences,Shanghai 201800,China [2]Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China

出　　处：《Chinese Optics Letters》2021年第4期82-87,共6页中国光学快报（英文版）

基　　金：supported by the National Natural Science Foundation of China (NSFC) (Nos. 11127901, 11134010, 61221064, and 61405222);the Strategic Priority Research Program of Chinese Academy of Sciences (CAS) (No. XDB16000000)。

摘　　要：We present a velocity-gauge model for the generation of even-order high harmonics, and reveal that the even-order harmonics originate from the multiple-step transitions among the energy bands in momentum space, while the odd-order harmonics are mainly from direct transitions. The lower valence band is found vital for the generation of even harmonics. Relative intensity of even-order harmonics versus the odd orders is calculated and shows a growing trend as the laser field amplitude increases.

关 键 词：solid high-harmonic generation inversion asymmetry even-order harmonics 

分 类 号：TH824[机械工程—仪器科学与技术]