Influence of photoexcited and thermal electrons and holes on generation of THz radiation in InAs in magnetic field

The theoretical description of THz radiation generation when InAs placed in a magnetic field and exposed to a femtosecond pulse is proposed. It is found that at moderate photoexcitation level of InAs, for the correct description of THz radiation generation, along with photoexcited particles, it is necessary to take into account the influence of thermal electrons and holes on the semiconductor dielectric permittivity. The contribution of electrons, light, heavy and split-off holes to the THz radiation generation is described in detail. If the cyclotron frequency of electrons \(\Omega _e\) does not exceed their plasma frequency \(\omega _{pe}\), the generated pulse contains oscillations at frequencies close to the frequencies \(\omega _{\pm }\), determining at small collision frequencies the lower and upper boundaries of the semiconductor transparency region in the magnetic field. If \(\Omega _e\) is greater than \(\omega _{pe}\), the oscillations at the frequency \(\omega _{+}\) remain, and the oscillations at the frequency \(\omega _{-}\) are suppressed due to the influence of heavy holes.