Validity of the Free Electron Model for Two-Dimensional Electrodes

ABSTRACTGenerally, the electrodes are regarded as free electron gases when we calculate the transport characteristics of nanostructure materials or devices. In three dimensional electrodes, there are little electron correlation. However, in low-dimensional electrodes, electron correlation becomes much larger than that in three dimensional ones. Recently, nanotechnology has made much progress to fabricate two-dimensional (2D) electrodes easily and precisely. As a result, we must consider whether two-dimensional electrodes can be regarded as free electron gases. In this study, we investigate the electron energy spectrum of 2D electrodes, taking into consideration the electron correlation. These results suggest that the free electron model is justified only at the Fermi momentum and that we should not regard 2D electrodes as free electron gases without careful consideration under high electric field and/or high temperature.