Abstarct: The effective application of optical and electron properties of nanostructures plays a central role in the development of electronics and optical electronics. An important part of the future applications of electron-beam and electron-baxsed electronic components in the presence of terahertz radiation and the electrical and magnetic fields in nano-structures will be. Therefore, the study of optical properties and nonlinear electron transport in nano-structures will be of particular importance. In this thesis, due to the effective role of electron-photon-phonon interactions, nonlinear electron transport in a quantum beam under terahertz radiation and the presence of a strong magnetic field perpendicular to the wire along the wire are studied theoretically. And by performing numerical calculations, the results of the three different regimes are displayed. By increasing the field intensity or the frequency of electron radiation, they absorb radiant energy and lose energy by phonon emission. But in low-intensity fields near the electron temperature near the sample temperature, the device responds linearly. In a nonlinear regime, with the increase of the magnetic field, the conductivity is reduced. This process of reducing conductivity can be attributed to the interaction of electron-phonon in the presence of a magnetic field.