Molecular-dynamics study of single-electron charging in semiconductor wires

A molecular-dynamics technique is applied to single-electron charging effects in semiconductor wires, and the impact of strong electron-electron correlation on the conductance is investigated. Because of the relatively low electron density in semiconductors compared to a metal, the screening length is comparable to the sample size, which requires a treatment beyond the conventional Coulomb-blockade argument using macroscopic capacitance. Based on the molecular-dynamics method, most features of the periodic conductance oscillation in the double-barrier system are reproduced, and the feasibility of this technique in single-electron charging phenomena is demonstrated. Experimental observation of an activation energy smaller than the threshold energy of the nonlinear conductance, which the normal Coulomb-blockade model cannot explain, is reproduced in the present approach. This effect is due to the strong microscopic correlation, so that this is essential to describe accurately the single-electron charging effects in semiconductor systems.