Energy band splitting and high-order harmonic generation from a doped semiconductor

We theoretically investigate the high-order harmonic generation (HHG) from laser–solid interaction in a doped semiconductor by solving the one-dimensional time-dependent Schrödinger equation within the single active electron model. The results show that the energy band of the valence and the low conduction band can be split into a small band in the doped semiconductor. The splitting band gap can be controlled by changing the depth of the potential well of the doped semiconductor, and the second HHG plateau can be enhanced. We also demonstrate the energy band structures in coordinate space with different numbers of dopant. Time-dependent population imaging is used to illustrate the change of the splitting band gap with different depths of the potential well of the doped semiconductor. (letter)