Simulation Of Nanostructures Research Articles

New transient modeling of an irreversible single-electron box and its application to a majority gate

This paper introduces an equivalent circuit model for an irreversible single-electron box (SEB) in HSPICE. This model is based on the orthodox theory and the solution to the master equation in the time domain. Using this model, we study the behavior of the device at low-frequencies and its hysteresis characteristic, and we compare the results with those of simulation of nano-structures (SIMON), considered as a reference. We observe that the results in the steady-state limit obtained from our model are completely identical to those of SIMON. In addition, the behaviors of the device at high-frequencies are calculated using the proposed model. To verify the results, they are compared with analytical solutions for a square-pulse input signal. We see that our circuit model also gives accurate results for transient calculations. As an applicable example, the proposed circuit model is applied to an irreversible SEB-based majority gate, and the time-dependent outputs are calculated.

A three-dimensional solver of the Schrödingerequation in momentum space for the detailed simulation ofnanostructures

We propose a simple method for computing the single-particleeigenfunctions in nanostructures with three-dimensionalconfinement. The proposed procedure transfers the problem to the momentum space, solves an eigenvalue equation on a reduced wavevectors space and then transfers the solution back to thereal space. We show that in such a way it is possible to obtainthe eigenvectors and eigenvalues corresponding to lower energieswith significant improvement in computing time and memoryrequirements with respect to numerical methods in the coordinatespace. The method can be applied to structures with inhomogeneouseffective mass and can easily include the full band structure.We have tested the code on typical confining potentials ofnanostructures, in order to show the advantages and possiblelimitations of the proposed method.