Electronic transmission of a nanowire partly irradiated under terahertz electromagnetic field

We theoretically study the electronic transport of a nanowire partly irradiated under an external terahertz (THz) electromagnetic field. Although the electrons in the ballistic nanowires only suffer lateral collision with photons the reflection of electrons also takes place in this partly irradiated case. Using free-electron model and scattering matrix approach we showed that at resonance there exists a step decrement of 50 percent for the transmission probability as the amplitude of field increases to a certain volume. And the coherent structure of transmission for the system apparently appears when the field irradiate the middle part of nanowire only. This sensitive transmission property of the system may be used in the THz detection.