PHONON-ASSISTED BALLISTIC RESISTANCE

We investigate the influence of phonons on the ballistic transport in idealized semiconductor structures. We examine the onset of the collision-controlled transport and estimate the critical temperature interval that separates ballistic and fully collision-controlled transport. For this purpose, we calculate the variation G of the ballistic conductance G, which is due to electron-phonon interactions. For the simple case of a spatially uniform conductor we find the dependence of G on temperature, wire width, and chemical potential. We also find oscillations in G at sufficiently low temperatures due to quantum size effects. We come to the striking conclusion that even at temperatures as high as 77 K the phonon-assisted part may still be small as compared to the total ballistic resistance, although the oscillations may die away at much lower temperature. At low temperatures the uppermost current carrying channels provide the major contribution to the part of resistance that is due to the electron-phonon interactions. © 1995 The American Physical Society.