  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.

Mesoscale and Nanoscale Physics;Materials Science