Simulating the Effect of Spatial Potential Variation in Nanodevices with the NEGF Method

Abstract: In this master thesis nanowires have been simulated to study the effect of spatial imperfections in the nanowires. This spatial imper- fection took the form of potential fluctuations in the conduction band across the wire. To achieve this, scripts were written in MATLAB to simulate the nanodevices by applying the non-equilibrium Green’s function (NEGF) method. To verify the simulations, multiple quantum phenomena were reproduced in simulations. To reduce the data-size of the simulation results, a compression algorithm based on the Quite OK Image Format (QOI) was also developed. The simulations were able to qualitatively reproduce quantum tun- neling and quantum point conductance. The simulations showed that increasing the amplitude of the applied potential noise to the nanowire had a bigger impact on the conductance of a nanowire than the cor- relation length of the noise. The noise had a smaller impact on the quantum hall effect than the transmission. Finally the compression algorithm was able to reduce the data size of the results with a worst case scenario of 84.9% and best case scenario reaching 97.8% while having minimal effect on the result.