Role of virtual band population for high harmonic generation in solids
Role of virtual band population for high harmonic generation in solids
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DOI：
10.1103/physrevb.102.041125
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发表时间：
2020-07
影响因子：
3.7
通讯作者：
Yasuyuki Sanari;H. Hirori;T. Aharen;H. Tahara;Y. Shinohara;K. Ishikawa;T. Otobe;Peiyu Xia;
中科院分区：
文献类型：
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作者：
Yasuyuki Sanari;H. Hirori;T. Aharen;H. Tahara;Y. Shinohara;K. Ishikawa;T. Otobe;Peiyu Xia;
研究了甲基铵三氯化铅单晶的亚带隙高次谐波产生。观察到晶体取向对高次谐波产额的各向异性，并且高次谐波产额随用于激发的中红外激光脉冲的电场强度而变化。我们的实时从头算模拟很好地再现了实验结果，也表明高次谐波与带间退相干时间无关。基于带内电流的微观分析，我们揭示了这种钙钛矿半导体中HHG的取向依赖关系是由虚带布居决定的，而不是电子带结构的非谐性。
We study the sub-band-gap high harmonic generation (HHG) in a methylammonium lead trichloride single crystal. Anisotropy in the crystal orientation dependence of the high harmonic yield is observed, and the yield varies substantially with the electric field strength of the midinfrared laser pulse used for excitation. Our real-time ab initio simulations reproduce the experimental results well and also show that the HHG is independent of the interband decoherence time. Based on a microscopic analysis of the intraband current, we reveal that the orientation dependence of the HHG in this perovskite semiconductor is governed by the virtual band population, rather than the anharmonicity of the electronic band structure.