Opt Express. 2023 Mar 13;31(6):9817-9826. doi: 10.1364/OE.483254.
High harmonic generation from bilayer h-BN materials with different stacking configurations is theoretically investigated by solving the extended multiband semiconductor Bloch equations in strong laser fields. We find that the harmonic intensity of AA'-stacking bilayer h-BN is one order of magnitude higher than that of AA-stacking bilayer h-BN in high energy region. The theoretical analysis shows that with broken mirror symmetry in AA'-stacking, electrons have much more opportunities to transit between each layer. The enhancement in harmonic efficiency originates from additional transition channels of the carriers. Moreover, the harmonic emission can be dynamically manipulated by controlling the carrier envelope phase of the driving laser and the enhanced harmonics can be utilized to achieve single intense attosecond pulse.
双层 h-BN 材料在不同堆叠结构下的高次谐波产生，通过在强激光场中求解扩展多带半导体布洛赫方程进行了理论研究。我们发现，在高能区，AA'堆叠双层 h-BN 的谐波强度比 AA 堆叠双层 h-BN 高一个数量级。理论分析表明，在 AA'堆叠中，由于镜像对称被打破，电子在各层之间跃迁的机会大大增加。谐波效率的提高源于载流子的附加跃迁通道。此外，通过控制驱动激光的载波包络相位，可以动态地控制谐波发射，并且可以利用增强的谐波来实现单个强的阿秒脉冲。
