A Wigner equation for the nanometer and femtosecond transport regime

We present a quantum-kinetic equation which describes the transport phenomena in nanoelectronic devices. The equation can be regarded as a generalization of the Boltzmann equation, which describes the operation of the conventional microelectronic devices. The presented equation treats the coherent part of the transport imposed by the nanostructure potential on a rigorous quantum level, utilizing the Wigner picture. It is shown that the equation is general enough to account for quantum effects in the dissipative part of the transport imposed by the electron-phonon interaction. Numerical experiments demonstrate the effects of collision broadening, retardation and the intra-collisional field effect. Theoretical analysis of the equation reveals a novel quantum effect which is due to the correlation between the interaction process and the space component of the Wigner path.